Amicus Therapeutics (FOLD) 10-K 3 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 24, 2015	Jun. 30, 2014
Document and Entity Information
Entity Registrant Name	AMICUS THERAPEUTICS INC
Entity Central Index Key	1178879
Document Type	10-K
Document Period End Date	31-Dec-14
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$111,245,794
Entity Common Stock, Shares Outstanding		95,624,073
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$24,074	$43,640
Investments in marketable securities	127,601	38,360
Receivable due from collaboration agreements		1,083
Prepaid expenses and other current assets	2,902	5,195
Total current assets	154,577	88,278
Investments in marketable securities	17,464
Property and equipment, less accumulated depreciation and amortization of $11,520 and $9,973 at December 31, 2014 and 2013 respectively	2,811	4,120
In-process research & development	23,000	23,000
Goodwill	11,613	11,613
Other non-current assets	502	552
Total Assets	209,967	127,563
Current liabilities:
Accounts payable and accrued expenses	16,345	10,162
Current portion of secured loan	3,840	299
Total current liabilities	20,185	10,461
Deferred reimbursements	36,620	36,677
Secured loan, less current portion	10,510	14,174
Contingent consideration payable	10,700	10,600
Deferred tax liability	9,186	9,186
Other non-current liability	588	714
Commitments and contingencies
Stockholders' equity:
Common stock, $.01 par value, 125,000,000 shares authorized, 95,556,277 shares issued and outstanding at December 31, 2014 61,975,416 shares issued and outstanding at December 31, 2013	1,015	679
Additional paid-in capital	568,743	423,593
Accumulated other comprehensive income	-132	1
Accumulated Deficit	-447,448	-378,522
Total stockholders' equity	122,178	45,751
Total Liabilities and Stockholders' Equity	$209,967	$127,563

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Consolidated Balance Sheets
Accumulated depreciation and amortization of property and equipment (in dollars)	$11,520	$9,973
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issued	95,556,277	61,975,416
Common stock, shares outstanding	95,556,277	61,975,416

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue:
Research revenue	$1,224	$363	$11,591
Collaboration and milestone revenue			6,820
Total revenue	1,224	363	18,411
Operating Expenses:
Research and development	47,624	41,944	50,273
General and administrative	20,717	18,893	19,364
Changes in fair value of contingent consideration payable	100
Restructuring charges	-63	1,988
Depreciation and amortization	1,547	1,719	1,705
Total operating expenses	69,925	64,544	71,342
Loss from operations	-68,701	-64,181	-52,931
Other income (expenses):
Interest income	223	174	316
Interest expense	-1,484	-46	-89
Change in fair value of warrant liability		908	653
Other (expense)/income	-77		21
Loss before income tax benefit	-70,039	-63,145	-52,030
Income tax benefit	1,113	3,512	3,245
Net loss	-68,926	-59,633	-48,785
Net loss attributable to common stockholders	($68,926)	($59,633)	($48,785)
Net loss attributable to common stockholders per common share - basic and diluted	($0.93)	($1.16)	($1.07)
Weighted-average common shares outstanding - basic and diluted	74,444,157	51,286,059	45,565,217

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Loss (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Consolidated Statements of Comprehensive Loss
Net loss	($68,926)	($59,633)	($48,785)
Other comprehensive income/(loss):
Unrealized (loss)/ gain on available-for-sale securities	-133	-13	10
Other comprehensive (loss)/income before income taxes	-133	-13	10
Other comprehensive (loss)/income	-133	-13	10
Comprehensive loss	($69,059)	($59,646)	($48,775)

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Stockholders' Equity (USD $)	Common Stock	Additional Paid-In Capital	Other Comprehensive Gain/ (Loss)	Deficit Accumulated During the Development Stage	Total
In Thousands, except Share data, unless otherwise specified
Balance at Dec. 31, 2011	$407	$299,285	$4	($270,104)	$29,592
Balance (in shares) at Dec. 31, 2011	34,654,206
Increase (Decrease) in Stockholders' Equity
Stock issued from public offering	115	61,940			62,055
Stock issued from public offering (in shares)	11,500,000
Stock issued from collaboration agreement	29	18,111			18,140
Stock issued from collaboration agreement (in shares)	2,949,581
Stock issued from exercise of stock options, net	4	1,626			1,630
Stock issued from exercise of stock options, net (in shares)	436,952
Stock issued from exercise of warrants	1	386			387
Stock issued from exercise of warrants (in shares)	90,933
Stock-based compensation		6,191			6,191
Unrealized (loss)/ gain on available-for-sale securities			10		10
Net loss				-48,785	-48,785
Balance at Dec. 31, 2012	556	387,539	14	-318,889	69,220
Balance (in shares) at Dec. 31, 2012	49,631,672
Increase (Decrease) in Stockholders' Equity
Stock and warrants issued in financing	75	14,925			15,000
Stock and warrants issued in financing (in shares)	7,500,000
Stock issued for Callidus acquisition	48	14,952			15,000
Stock issued for Callidus acquisition (in shares)	4,843,744
Stock-based compensation		6,177			6,177
Unrealized (loss)/ gain on available-for-sale securities			-13		-13
Net loss				-59,633	-59,633
Balance at Dec. 31, 2013	679	423,593	1	-378,522	45,751
Balance (in shares) at Dec. 31, 2013	61,975,416				61,975,416
Increase (Decrease) in Stockholders' Equity
Stock issued from public offering	159	97,010			97,169
Stock issued from public offering (in shares)	15,927,500
Stock issued from ATM transactions	143	38,493			38,636
Stock issued from ATM transactions (in shares)	14,328,224
Stock issued from exercise of stock options, net	10	3,663			3,673
Stock issued from exercise of stock options, net (in shares)	965,544
Stock issued for Callidus acquisition	24	-24
Stock issued for Callidus acquisition (in shares)	2,359,593
Stock-based compensation		6,008			6,008
Unrealized (loss)/ gain on available-for-sale securities			-133		-133
Net loss				-68,926	-68,926
Balance at Dec. 31, 2014	$1,015	$568,743	($132)	($447,448)	$122,178
Balance (in shares) at Dec. 31, 2014	95,556,277				95,556,277

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating activities
Net loss	($68,926)	($59,633)	($48,785)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash interest expense	277
Depreciation and amortization	1,547	1,719	1,705
Stock-based compensation	6,008	6,177	6,191
Restructuring charges	-63	1,988
Change in fair value of warrant liability		-908	-653
Non-cash changes in the fair value of contingent consideration payable	100
Loss on disposal of asset			28
Changes in operating assets and liabilities:
Receivable due from collaboration agreements	1,083	2,142	1,818
Prepaid expenses and other current assets	2,293	-2,925	3,633
Other non-current assets	26		267
Accounts payable and accrued expenses	6,169	-613	-863
Non-current liabilities	-126
Deferred reimbursements	-57	6,259	2,915
Net cash used in operating activities	-51,669	-45,794	-33,744
Investing activities
Sale and redemption of marketable securities	55,914	83,337	83,352
Purchases of marketable securities	-162,752	-56,559	-118,459
Purchases of property and equipment	-238	-695	-4,324
Net cash (used in)/ provided by investing activities	-107,076	26,083	-39,431
Financing activities
Proceeds from the issuance of common stock and warrants, net of issuance costs	135,805	15,000	80,195
Payments of secured loan agreement	-299	-398	-1,342
Payments related to deferred financing		-110
Proceeds from exercise of stock options	3,673		1,630
Proceeds from secured loan agreement		14,888	995
Net cash provided by financing activities	139,179	29,380	81,478
Net (decrease)/ increase in cash and cash equivalents	-19,566	9,669	8,303
Cash and cash equivalents at beginning of year/period	43,640	33,971	25,668
Cash and cash equivalents at end of year/period	24,074	43,640	33,971
Supplemental disclosures of cash flow information
Cash paid during the period for interest	1,186	30	84
Non-cash activities
Conversion of warrants to common stock			$386

Description_of_Business

Description of Business	12 Months Ended
	Dec. 31, 2014
Description of Business
Description of Business
	1. Description of Business
	Corporate Information, Status of Operations, and Management Plans
	Amicus Therapeutics, Inc. (the "Company") was incorporated on February 4, 2002 in Delaware and is a biopharmaceutical company focused on the discovery, development and commercialization of next-generation medicines for a range of rare and orphan diseases, with a focus on improved therapies for lysosomal storage diseases ("LSDs"). The Company's lead product candidate is a small molecule that can be used as a monotherapy and in combination with enzyme replacement therapy ("ERT") for Fabry disease. The Company's development programs also include next-generation ERTs for LSDs, including Fabry disease, Pompe disease and Mucopolysaccharoidosis Type I (MPS I). The Company's activities since inception have consisted principally of raising capital, establishing facilities, and performing research and development.
	Throughout 2014 and in early 2015 we announced positive 12- and 24-months results from Study 011 and longer-term data from Study 041 in patients with amenable mutations who were naïve to ERT. Following a meeting with the European Medicines Agency ("EMA") held in the fourth quarter of 2014, the Company is on track to submit a marketing application in Europe in mid-2015. The Company has also scheduled a meeting with the US FDA in the first quarter of 2015 as it works to make migalastat available for all amenable Fabry patients as quickly as possible.
	In November 2014, the Company issued a total of 15.9 million shares through public offering at a price of $6.50 per share, with net proceeds of $97.2 million. The Company expects to use the net proceeds of the offering for investment in the global commercialization infrastructure for migalastat monotherapy for Fabry disease, the continued clinical development of its product candidates and for other general corporate purposes.
	In July 2014, the Company completed a $40 million at the market ("ATM") equity offering under which the Company sold shares of its common stock, par value $0.01 per share, with Cowen and Company LLC as sales agent. Under the ATM equity program, the Company sold 14.3 million shares of common stock raising approximately $38.6 million in net proceeds. For further information on the ATM Agreement, see "— Note 9. Stockholder's Equity".
	In November 2013, the Company completed the acquisition of Callidus Biopharma, Inc. ("Callidus"). Callidus was a privately-held biologics company focused on developing best-in-class ERTs for lysosomal storage diseases LSDs. Callidus lead ERT is a recombinant human acid-alpha glucosidase (rhGAA, called "ATB200") for Pompe disease in late preclinical development. For further information, see "— Note 3. Acquisition of Callidus Biopharma, Inc."
	In November 2013, the Company entered into the Revised Agreement (the "Revised Agreement") with GlaxoSmithKline plc ("GSK"), pursuant to which Amicus has obtained global rights to develop and commercialize migalastat as a monotherapy and in combination with ERT for Fabry disease. The Revised Agreement amends and replaces in its entirety the Expanded Agreement entered into between Amicus and GSK in July 2012 (the "Expanded Collaboration Agreement"). Under the terms of the Revised Agreement, Amicus obtained global commercial rights to migalastat, both as a monotherapy and co-formulated with ERT. For migalastat monotherapy, GSK is eligible to receive post-approval and sales-based milestones, as well as tiered royalties in the mid-teens in eight major markets outside the U.S. There was no other consideration paid to GSK as part of the Revised Agreement.
	In November 2013, the Company entered into a securities purchase agreement (the "2013 SPA") with GSK and certain entities controlled by Redmile Group, LLC for the private placement of a combination of shares of the Company's common stock and warrants to purchase shares of the Company's common stock. The warrants have a term of one year and are exercisable between July 1, 2014 and June 30, 2015 at an exercise price of $2.50 per share. The aggregate offer proceeds were $15 million. In October 2014, GSK sold all their shares and no longer have an ownership position in the Company as of December 31, 2014.
	In September 2013, the Company entered into a collaboration agreement with Biogen Idec ("Biogen") to discover, develop and commercialize novel small molecules that target the glucocerobrosidase ("GCase") enzyme for the treatment of Parkinson's disease. In September 2014, the Company and Biogen concluded their research collaboration. Amicus' most advanced Parkinson's candidate is AT3375, which was developed outside the collaboration and is wholly-owned by Amicus. For further information, see "— Note 15. Collaborative Agreements."
	The Company had an accumulated deficit of approximately $447.4 million at December 31, 2014 and anticipates incurring losses through the fiscal year ending December 31, 2015 and beyond. The Company has not yet generated commercial sales revenue and has been able to fund its operating losses to date through the sale of its redeemable convertible preferred stock, issuance of convertible notes, net proceeds from its initial public offering ("IPO") and subsequent stock offerings, payments from partners during the terms of the collaboration agreements and other financing arrangements. The Company believes that its existing cash and cash equivalents and short-term investments will be sufficient to fund the current operating plan into 2017.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies
	2. Summary of Significant Accounting Policies
	Basis of Presentation
	The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles ("U.S.GAAP") and include all adjustments necessary for the fair presentation of the Company's financial position for the periods presented.
	Consolidation
	The financial statements include the accounts of Amicus Therapeutics, Inc. and its wholly owned subsidiaries, Amicus Therapeutics UK Limited and Callidus Biopharma, Inc. All significant intercompany transactions and balances are eliminated in consolidation. These subsidiaries are not material to the overall financial statements of the Company.
	Use of Estimates
	The preparation of financial statements in conformity with U.S.GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates.
	Cash, Money Market Funds, and Marketable Securities
	The Company considers all highly liquid investments purchased with a maturity of three months or less at the date of acquisition, to be cash equivalents.
	Marketable securities consist of fixed income investments with a maturity of greater than three months and other highly liquid investments that can be readily purchased or sold using established markets. These investments are classified as available-for-sale and are reported at fair value on the Company's balance sheet. Unrealized holding gains and losses are reported within comprehensive income/ (loss) in the statements of comprehensive loss. Fair value is based on available market information including quoted market prices, broker or dealer quotations or other observable inputs. See "— Note 6. Cash, Money Market Funds and Marketable Securities", for a summary of available-for-sale securities as of December 31, 2014 and 2013.
	Concentration of Credit Risk
	The Company's financial instruments that are exposed to concentration of credit risk consist primarily of cash and cash equivalents and marketable securities. The Company maintains its cash and cash equivalents in bank accounts, which, at times, exceed federally insured limits. The Company invests its marketable securities in high-quality commercial financial instruments. The Company has not recognized any losses from credit risks on such accounts during any of the periods presented. The Company believes it is not exposed to significant credit risk on cash and cash equivalents or its marketable securities.
	Property and Equipment
	Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation is calculated over the estimated useful lives of the respective assets, which range from three to five years, or the lesser of the related initial term of the lease or useful life for leasehold improvements. Assets under capital leases are amortized over the terms of the related leases or their estimated useful lives, whichever is shorter.
	The initial cost of property and equipment consists of its purchase price and any directly attributable costs of bringing the asset to its working condition and location for its intended use. Expenditures incurred after the fixed assets have been put into operation, such as repairs and maintenance, are charged to income in the period in which the costs are incurred. Major replacements, improvements and additions are capitalized in accordance with Company policy.
	Revenue Recognition
	The Company recognizes revenue when amounts are realized or realizable and earned. Revenue is considered realizable and earned when the following criteria are met: (1) persuasive evidence of an arrangement exists; (2) delivery has occurred or services have been rendered; (3) the price is fixed or determinable; and (4) collection of the amounts due are reasonably assured.
	In multiple element arrangements, revenue is allocated to each separate unit of accounting and each deliverable in an arrangement is evaluated to determine whether it represents separate units of accounting. A deliverable constitutes a separate unit of accounting when it has standalone value and there is no general right of return for the delivered elements. In instances when the aforementioned criteria are not met, the deliverable is combined with the undelivered elements and the allocation of the arrangement consideration and revenue recognition is determined for the combined unit as a single unit of accounting. Allocation of the consideration is determined at arrangement inception on the basis of each unit's relative selling price. In instances where there is determined to be a single unit of accounting, the total consideration is applied as revenue for the single unit of accounting and is recognized over the period of inception through the date where the last deliverable within the single unit of accounting is expected to be delivered.
	The Company's current revenue recognition policies, provide that, when a collaboration arrangement contains multiple deliverables, such as license and research and development services, the Company allocates revenue to each separate unit of accounting based on a selling price hierarchy. The selling price hierarchy for a deliverable is based on (i) its vendor specific objective evidence ("VSOE") if available, (ii) third party evidence ("TPE") if VSOE is not available, or (iii) best estimated selling price ("BESP") if neither VSOE nor TPE is available. The Company would establish the VSOE of selling price using the price charged for a deliverable when sold separately. The TPE of selling price would be established by evaluating largely similar and interchangeable competitor products or services in standalone sales to similarly situated customers. The BESP would be established considering internal factors such as an internal pricing analysis or an income approach using a discounted cash flow model.
	The Company also considers the impact of potential future payments it makes in its role as a vendor to its customers and evaluates if these potential future payments could be a reduction of revenue from that customer. If the potential future payments to the customer are:
	•	a payment for an identifiable benefit; and
	•	the identifiable benefit is separable from the existing relationship between the Company and its customer; and
	•	the identifiable benefit can be obtained from a party other than the customer; and
	•	the Company can reasonably estimate the fair value of the identifiable benefit
	then the payments are accounted for separate from the revenue received from that customer. If, however, all these criteria are not satisfied, then the payments are treated as a reduction of revenue from that customer.
	If the Company determines that any potential future payments to its customers are to be considered as a reduction of revenue, it must evaluate if the total amount of revenue to be received under the arrangement is fixed and determinable. If the total amount of revenue is not fixed and determinable due to the uncertain nature of the potential future payments to the customer, then any customer payments cannot be recognized as revenue until the total arrangement consideration becomes fixed and determinable.
	The reimbursements for research and development costs under collaboration agreements that meet the criteria for revenue recognition are included in Research Revenue and the costs associated with these reimbursable amounts are included in research and development expenses.
	In order to determine the revenue recognition for contingent milestones, the Company evaluates the contingent milestones using the criteria as provided by the Financial Accounting Standards Boards ("FASB") guidance on the milestone method of revenue recognition at the inception of a collaboration agreement. The criteria requires that (i) the Company determines if the milestone is commensurate with either its performance to achieve the milestone or the enhancement of value resulting from the Company's activities to achieve the milestone, (ii) the milestone be related to past performance, and (iii) the milestone be reasonable relative to all deliverable and payment terms of the collaboration arrangement. If these criteria are met then the contingent milestones can be considered as substantive milestones and will be recognized as revenue in the period that the milestone is achieved.
	Fair Value Measurements
	The Company records certain asset and liability balances under the fair value measurements as defined by the FASB guidance. Current FASB fair value guidance emphasizes that fair value is a market-based measurement, not an entity-specific measurement. Therefore, a fair value measurement should be determined based on the assumptions that market participants would use in pricing the asset or liability. As a basis for considering market participant assumptions in fair value measurements, current FASB guidance establishes a fair value hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity (observable inputs that are classified within Levels 1 and 2 of the hierarchy) and the reporting entity's own assumptions that market participants assumptions would use in pricing assets or liabilities (unobservable inputs classified within Level 3 of the hierarchy).
	Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at measurement date. Level 2 inputs are inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs may include quoted prices for similar assets and liabilities in active markets, as well as inputs that are observable for the asset or liability (other than quoted prices), such as interest rates, foreign exchange rates, and yield curves that are observable at commonly quoted intervals. Level 3 inputs are unobservable inputs for the asset or liability, which is typically based on an entity's own assumptions, as there is little, if any, related market activity. In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety. The Company's assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset or liability.
	Research and Development Costs
	Research and development costs are expensed as incurred. Research and development expense consists primarily of costs related to personnel, including salaries and other personnel related expenses, consulting fees and the cost of facilities and support services used in drug development. Assets acquired that are used for research and development and have no future alternative use are expensed as in-process research and development.
	Interest Income and Interest Expense
	Interest income consists of interest earned on the Company's cash and cash equivalents and marketable securities. Interest expense consists of interest incurred on capital leases and secured debt.
	Income Taxes
	The Company accounts for income taxes under the liability method. Under this method deferred income tax liabilities and assets are determined based on the difference between the financial statement carrying amounts and tax basis of assets and liabilities and for operating losses and tax credit carry forwards, using enacted tax rates in effect in the years in which the differences are expected to reverse. A valuation allowance is recorded if it is "more likely than not" that a portion or all of a deferred tax asset will not be realized.
	Other Comprehensive Income/ (Loss)
	Components of other comprehensive income/ (loss) include unrealized gains and losses on available-for-sale securities and are included in the statements of comprehensive loss.
	Leases
	In the ordinary course of business, the Company enters into lease agreements for office space as well as leases for certain property and equipment. The leases have varying terms and expirations and have provisions to extend or renew the lease agreement, among other terms and conditions, as negotiated. Once the agreement is executed, the lease is assessed to determine whether the lease qualifies as a capital or operating lease.
	When a non-cancelable operating lease includes any fixed escalation clauses and lease incentives for rent holidays or build-out contributions, rent expense is recognized on a straight-line basis over the initial term of the lease. The excess between the average rental amount charged to expense and amounts payable under the lease is recorded in accrued expenses.
	Nonqualified Cash Deferral Plan
	In July 2014, the Board of Directors approved the Company's Cash Deferral Plan (the "Deferral Plan"), which provides certain key employees and members of the Board of Directors as selected by the Compensation Committee of the Board of Directors of the Company (the "Compensation Committee"), with an opportunity to defer the receipt of such Participant's base salary, bonus and director's fees, as applicable. The Deferral Plan is intended to be a nonqualified deferred compensation plan that complies with the provisions of Section 409A of the Internal Revenue Code (the "Code").
	As of December 31, 2014, the amounts deferred under the Deferral Plan have not been invested. The investments are expected to be made in the first quarter of fiscal year 2015. All of the investments held in the Deferral Plan will be classified as trading securities and recorded at fair value with changes in the investments' fair value recognized as earnings in the period they occur. The corresponding liability for the Deferral Plan is included in other non-current liability in our consolidated balance sheets.
	Equity Incentive Plan
	In June 2014, our stockholders approved the Amended and Restated 2007 Equity Incentive Plan (the "Plan"). The amendment to the Plan makes an additional 6.0 million shares of our common stock available for issuance and increases the maximum number of shares within the Plan that may be issued as restricted stock, restricted stock units ("RSUs"), stock grants and any other similar awards from 1.1 million to 1.5 million shares. As of December 31, 2014, awards issued under the Plan include both stock options and RSUs.
	Stock-Based Compensation
	At December 31, 2014, the Company had three stock-based employee compensation plans, which are described more fully in "— Note 9. Stockholders' Equity." The Company applies the fair value method of measuring stock-based compensation, which requires a public entity to measure the cost of employee services received in exchange for an award of equity instruments based on the grant-date fair value of the award.
	Loss per Common Share
	The Company calculates net loss per share as a measurement of the Company's performance while giving effect to all dilutive potential common shares that were outstanding during the reporting period. The Company had a net loss for all periods presented; accordingly, the inclusion of common stock options, unvested restricted stock units ("RSUs") and warrants would be anti-dilutive. Therefore, the weighted average shares used to calculate both basic and diluted earnings per share are the same. See "— Note 19. Earnings per Share" for further discussion on net loss per share.
	Dividends
	The Company has not paid cash dividends on its capital stock to date. The Company currently intends to retain its future earnings, if any, to fund the development and growth of the business and does not foresee payment of a dividend in any upcoming fiscal period.
	Segment Information
	The Company currently operates in one business segment focusing on the development and commercialization of small molecule, orally administered therapies to treat a range of human genetic diseases. The Company is not organized by market and is managed and operated as one business. A single management team reports to the chief operating decision maker who comprehensively manages the entire business. The Company does not operate any separate lines of business or separate business entities with respect to its products. Accordingly, the Company does not accumulate discrete financial information with respect to separate service lines and does not have separately reportable segments.
	Business Combinations
	The Company allocates the purchase price of acquired businesses to the tangible and intangible assets acquired and liabilities assumed based upon their estimated fair values on the acquisition date. The purchase price allocation process requires management to make significant estimates and assumptions, especially at the acquisition date with respect to intangible assets and in-process research and development ("IPR&D"). In connection with the purchase price allocations for acquisitions, the Company estimates the fair value of contingent payments utilizing a probability-based income approach inclusive of an estimated discount rate.
	Contingent Consideration Payable
	The Company determines the fair value of contingent acquisition consideration payable on the acquisition date using a probability-based income approach utilizing an appropriate discount rate. Contingent acquisition consideration payable is shown as a non-current liability on the Company's consolidated balance sheets. Changes in the fair value of the contingent acquisition consideration payable will be determined each period end and recorded on the consolidated statements of operations.
	Intangible Assets and Goodwill
	The Company records goodwill in a business combination when the total consideration exceeds the fair value of the net tangible and identifiable intangible assets acquired. Purchased IPR&D is accounted for as an indefinite lived intangible asset until the underlying project is completed, at which point the intangible asset will be accounted for as a definite lived intangible asset, or abandoned, at which point the intangible asset will be written off or partially impaired. Goodwill and indefinite lived intangible assets are assessed annually for impairment and whenever events or circumstances indicate that the carrying amount of an asset may not be recoverable. If it is determined that the full carrying amount of an asset is not recoverable, an impairment loss is recorded in the amount by which the carrying amount of the asset exceeds its fair value.
	Restructuring
	Restructuring charges are recognized as a result of actions to streamline operations and rationalize manufacturing facilities. Judgment is used when estimating the impact of restructuring plans, including future termination benefits and other exit costs to be incurred when the actions take place. Actual results could vary from these estimates.
Recent Accounting Pronouncements
In November 2014, the FASB issued ASU 2014-17, Business Combinations (Topic 805): Pushdown Accounting which provides an acquired entity with the option to apply pushdown accounting in its separate financial statements upon occurrence of an event in which an acquirer obtains control of the acquired entity. The ASU is effective on November 18, 2014. After the effective date, an acquired entity can make an election to apply the guidance to future change-in-control events or to its most recent change-in-control event. However, if the financial statements for the period in which the most recent change-in-control event occurred already have been issued or made available to be issued, the application of this guidance would be a change in accounting principle. The Company is currently assessing the impact that this standard will have on its consolidated financial statements.
In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements-Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern, which defines management's responsibility to assess an entity's ability to continue as a going concern, and to provide related footnote disclosures if there is substantial doubt about its ability to continue as a going concern. The pronouncement is effective for annual reporting periods ending after December 15, 2016 with early adoption permitted. The adoption of this guidance is not expected to have a significant impact on the Company's consolidated financial state.
In June 2014, the FASB issued ASU 2014-10 that removes the definition of development stage entity from the accounting standards codification, thereby removing the financial reporting distinction between development stage entities and other reporting entities from U.S. GAAP. In addition, the ASU eliminates the requirements for development stage entities to (i) present inception-to-date information in the statement of income, cash flow and stockholders' equity, (ii) label the financial statements as those of a development stage entity, (iii) disclose a description of the development stage activities in which the entity is engaged, and (iv) disclose in the first year in which the entity is no longer a development stage entity that in prior years it had been in the development stage. The Company has applied the ASU to its financial statements as of June 30, 2014.
In May 2014, FASB issued ASU 2014-09, Revenue From Contracts With Customers, that outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. The ASU is based on the principle that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The ASU also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to fulfill a contract. Entities have the option of using either a full retrospective or a modified retrospective approach for the adoption of the new standard. The ASU becomes effective for the Company at the beginning of its 2017 fiscal year; early adoption is not permitted. The Company is currently assessing the impact that this standard will have on its consolidated financial statements.

Acquisition_of_Callidus_Biopha

Acquisition of Callidus Biopharma, Inc.	12 Months Ended
	Dec. 31, 2014
Acquisition of Callidus Biopharma, Inc.
Acquisition of Callidus Biopharma, Inc.
	3. Acquisition of Callidus Biopharma, Inc.
	In November 2013, the Company acquired Callidus, through the merger of the Company's subsidiary, CB Acquisition Corp. with and into Callidus (see "— Note 1. Description of Business"). Callidus was a privately-held biologics company focused on developing best-in-class ERTs for LSDs and its lead ERT is ATB200 for Pompe disease in late preclinical development. The acquisition of the Callidus assets and technology compliments Amicus' CHART™ platform for the development of next generation ERTs.
	In consideration for the merger, the Company agreed to issue an aggregate of 7.2 million shares of its common stock, par value $0.01 per share, to the former stockholders of Callidus. As of December 31, 2014, approximately 25 thousand shares remain issuable to former Callidus stockholders. In addition, the Company will be obligated to make additional payments to the former stockholders of Callidus upon the achievement by Callidus of certain clinical milestones of up to $35 million and regulatory approval milestones of up to $105 million as set forth in the Merger Agreement, provided that the aggregate consideration shall not exceed $130 million. The Company may, at its election, satisfy certain milestone payments identified in the Merger Agreement aggregating $40 million in shares of its Common Stock (calculated based on a price per share equal to the average of the last closing bid price per share for the Common Stock on The NASDAQ Global Market for the ten (10) trading days immediately preceding the date of payment). The milestone payments not permitted to be satisfied in Common Stock (as well as any payments that the Company is permitted to, but chooses not to, satisfy in Common Stock), as a result of the terms of the Merger Agreement, the rules of The NASDAQ Global Market, or otherwise, will be paid in cash.
	The fair value of the contingent acquisition consideration payments on the acquisition date was $10.6 million and was estimated by applying a probability-based income approach utilizing an appropriate discount rate. This estimation was based on significant inputs that are not observable in the market, referred to as Level 3 inputs. Key assumptions included a discount rate of 13.0% and various probability factors. As of December 31, 2014, the range of outcomes and assumptions used to develop these estimates has changed to better reflect the probability of certain milestone outcomes. (see "— Note 10. Assets and Liabilities Measured at Fair Value", for additional discussion regarding fair value measurements of the contingent acquisition consideration payable). The Company determined the fair value of the contingent consideration to be $10.7 million at December 31, 2014, resulting in an increase in the contingent consideration payable and related income of $0.1 million for the year ended December 31, 2014.
	The following table presents the allocation of the purchase consideration, including the contingent acquisition consideration payable, based on fair value:
		(in thousands)
	Upfront equity payments	$	15,000
	Contingent acquisition consideration payable		10,600
	Total consideration		25,600
	Cash and cash equivalents		34
	Property, plant and equipment		173
	Intangible assets — IPR&D		23,000
	Total identifiable assets acquired	$	23,207
	Accounts payable		(34	)
	Deferred tax liability		(9,186	)
	Total liabilities assumed		(9,220	)
	Net identifiable assets acquired		13,987
	Goodwill		11,613
	Net assets acquired	$	25,600
	A substantial portion of the assets acquired consisted of intangible assets related to Callidus lead ERT. The Company determined that the estimated acquisition-date fair values of the IPR&D related to the lead ERT was $23.0 million.
	The $9.2 million of deferred tax liabilities relates to the tax impact of future amortization or possible impairments associated with the identified intangible assets acquired, which are not deductible for tax purposes. The goodwill results from the recognition of the deferred tax liability on the intangible assets as well as synergies expected from the acquisition and other benefits that do not qualify for separate recognition as acquired intangible assets. None of the goodwill is expected to be deductible for income tax purposes. The Company recorded the goodwill in the Company's consolidated balance sheet as of the acquisition date.
	The Company recognized $0.5 million of acquisition-related transaction costs in selling, general and administrative expenses during 2013, which consisted primarily of legal fees and severance related to the acquisition.
	The results of operations of Callidus since November 19, 2013 have been included in the Company's consolidated statements of operations and are de minimis as of December 31, 2013.
	The following unaudited consolidated pro forma financial information presents the combined results of operations of the Company and Callidus as if the acquisition had occurred as of January 1, 2013. The unaudited pro forma consolidated financial information is not necessarily indicative of what the Company's consolidated results of operations actually would have been had the acquisition been completed as of January 1, 2013. In addition, the unaudited pro forma consolidated financial information does not attempt to project the future results of operations of the Company combined with Callidus.
		Years Ended
		December 31,
	Unaudited Pro Forma Consolidated Information:	2013			2012
	(in thousands)
	Revenue	$	363		$	18,411
	Net income (loss)	$	(61,804	)	$	(49,807	)

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2014
Goodwill
Goodwill
	4. Goodwill
	In connection with the acquisition of Callidus as discussed in "— Note 3. Acquisition of Callidus Biopharma, Inc.", the Company recognized goodwill of $11.6 million. Goodwill is assessed annually for impairment on October 1 and whenever events or circumstances indicate that the carrying amount of an asset may not be recoverable. If it is determined that the full carrying amount of an asset is not recoverable, an impairment loss is recorded in the amount by which the carrying amount of the asset exceeds its fair value. During the 2014 impairment assessment, it was determined that the goodwill had not been impaired thus there were no changes to the goodwill balance in 2014.

Intangible_Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2014
Intangible Assets
Intangible Assets
	5. Intangible Assets
	In connection with the acquisition of Callidus as discussed in "— Note 3. Acquisition of Callidus Biopharma, Inc.", the Company recognized IPR&D of $23.0 million. Intangible assets related to IPR&D assets are considered to be indefinite-lived until the completion or abandonment of the associated research and development efforts. During the period the assets are considered indefinite-lived, they will not be amortized but will be tested for impairment on an annual basis on October 1 and between annual tests if the Company becomes aware of any events occurring or changes in circumstances that would indicate a reduction in the fair value of the IPR&D assets below their respective carrying amounts. During the 2014 impairment assessment, it was determined that the IPR&D had not been impaired thus there was no change in the IPR&D balance in 2014.

Cash_Money_Market_Funds_and_Ma

Cash, Money Market Funds and Marketable Securities	12 Months Ended
	Dec. 31, 2014
Cash, Money Market Funds and Marketable Securities
Cash, Money Market Funds and Marketable Securities
	6. Cash, Money Market Funds and Marketable Securities
	As of December 31, 2014, the Company held $24.1 million in cash and cash equivalents and $145.1 million of available-for-sale securities which are reported at fair value on the Company's balance sheet. Unrealized holding gains and losses are reported within accumulated other comprehensive income/ (loss) in the statements of comprehensive loss. If a decline in the fair value of a marketable security below the Company's cost basis is determined to be other than temporary, such marketable security is written down to its estimated fair value as a new cost basis and the amount of the write-down is included in earnings as an impairment charge. To date, only temporary impairment adjustments have been recorded.
	Consistent with the Company's investment policy, the Company does not use derivative financial instruments in its investment portfolio. The Company regularly invests excess operating cash in deposits with major financial institutions, money market funds, notes issued by the U.S. government, as well as fixed income investments and U.S. bond funds both of which can be readily purchased and sold using established markets. The Company believes that the market risk arising from its holdings of these financial instruments is mitigated as many of these securities are either government backed or of the highest credit rating. Investments that have original maturities of greater than 3 months but less than 1 year are classified as short-term and investments with maturities that are greater than 1 year are classified as long-term.
	Cash and available for sale securities consisted of the following as of December 31, 2014 and December 31, 2013 (in thousands):
		As of December 31, 2014
		Cost			Unrealized			Unrealized			Fair
					Gain			Loss			Value
	Cash balances	$	24,074		$	—		$	—		$	24,074
	Corporate debt securities, current portion		115,862			—			(110	)		115,752
	Corporate debt securities, non-current portion		17,508			—			(44	)		17,464
	Commercial paper		11,477			22			—			11,499
	Certificate of deposit		350			—			—			350
		$	169,271		$	22		$	(154	)	$	169,139
	Included in cash and cash equivalents	$	24,074		$	—		$	—		$	24,074
	Included in marketable securities		145,197			22			(154	)		145,065
	Total cash and marketable securities	$	169,271		$	22		$	(154	)	$	169,139
		As of December 31, 2013
		Cost			Unrealized			Unrealized			Fair
					Gain			Loss			Value
	Cash balances	$	43,640		$	—		$	—		$	43,640
	Corporate debt securities		30,817			1			(6	)		30,812
	Commercial paper		7,192			6			—			7,198
	Certificate of deposit		350			—			—			350
		$	81,999		$	7		$	(6	)	$	82,000
	Included in cash and cash equivalents	$	43,640		$	—		$	—		$	43,640
	Included in marketable securities		38,359			7			(6	)		38,360
	Total cash and marketable securities	$	81,999		$	7		$	(6	)	$	82,000
	Unrealized gains and losses are reported as a component of other comprehensive gain/ (loss) in the statements of comprehensive loss. For the year ended December 31, 2014 and 2013, unrealized holding loss of $132 thousand and $13 thousand respectively, were included in the statements of comprehensive loss.
	For the years ended December 31, 2014 and 2013, there were no realized gains or losses. The cost of securities sold is based on the specific identification method.
	Unrealized loss positions in the available for sale securities as of December 31, 2014 and December 31, 2013 reflect temporary impairments that have been in a loss position for less than twelve months and as such are recognized in other comprehensive gain/ (loss). The fair value of these available for sale securities in unrealized loss positions was $129.2 million and $23.6 million as of December 31, 2014 and 2013, respectively.
	The Company holds available-for-sale investment securities which are reported at fair value on the Company's balance sheet. Unrealized holding gains and losses are reported within accumulated other comprehensive income ("AOCI") in the statements of comprehensive loss. The changes in AOCI associated with the unrealized holding gain on available-for-sale investments during the years ended December 31, 2014 and 2013, were as follows (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Balance, beginning	$	1		$	14		$	4
	Current period changes in fair value,		(133	)		(13	)		10
	Reclassification of earnings,		—			—			—
	Balance, ending	$	(132	)	$	1		$	14

Property_and_Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2014
Property and Equipment
Property and Equipment
	7. Property and Equipment
	Property and equipment consist of the following (in thousands):
		December 31,
		2014			2013
	Property and equipment consist of the following:
	Computer equipment	$	3,555		$	3,537
	Computer software		1,102			1,064
	Research equipment		5,986			5,918
	Furniture and fixtures		1,547			1,527
	Leasehold improvements		2,141			2,047
			14,331			14,093
	Less accumulated depreciation and amortization		(11,520	)		(9,973	)
		$	2,811		$	4,120
	Depreciation and amortization expense was $1.5 million and $1.7 million each for the years ended December 31, 2014 and 2013, respectively. There were no capital lease obligations outstanding as of December 31, 2014.

Accounts_Payable_and_Accrued_E

Accounts Payable and Accrued Expenses	12 Months Ended
	Dec. 31, 2014
Accounts Payable and Accrued Expenses
Accounts Payable and Accrued Expenses
	8. Accounts Payable and Accrued Expenses
	Accounts payable and accrued expenses consist of the following (in thousands):
		December 31,
		2014		2013
	Accounts payable	$	5,874	$	2,146
	Accrued professional fees		473		498
	Accrued contract manufacturing & contract research costs		3,321		1,499
	Accrued compensation and benefits		5,051		4,781
	Accrued facility costs		557		963
	Contingent success fee payable		341		—
	Accrued other		728		275
		$	16,345	$	10,162
	Other long-term liabilities consist of the following (in thousands):
		December 31,
		2014		2013
	Exit fees	$	450	$	450
	Success fees		—		264
	Employee compensation and benefits		124		—
	Security deposits		14		—
		$	588	$	714

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity
Stockholders' Equity
	9. Stockholders' Equity
	Common Stock and Warrants
	As of December 31, 2014, the Company was authorized to issue 125 million shares of common stock. Dividends on common stock will be paid when, and if declared by the board of directors. Each holder of common stock is entitled to vote on all matters that are appropriate for stockholder voting and is entitled to one vote for each share held.
	In November 2014, we sold a total of 15.9 million shares of our common stock, par value $0.01 per share, at a public offering price of $6.50 per share. The offering generated gross proceeds of $103.5 million. J.P. Morgan Securities LLC acted as sole book-running manager for the offering. Cowen and Company, LLC, Leerink Partners and Janney Montgomery Scott LLC acted as lead managers for the offering. After deducting the underwriting fee of $6.2 million and other offering expenses of $0.1 million, which included legal fees, the net proceeds of the offering were approximately $97.2 million. We expect to use the net proceeds of the offering for investment in the global commercialization infrastructure for migalastat monotherapy for Fabry disease, the continued clinical development of its product candidates and for other general corporate purposes.
	In March 2014, the Company entered into the Sales Agreement with Cowen to create an ATM equity program under which the Company sold shares of its common stock, par value $0.01 per share, with an aggregate offering price of up to $40 million ("ATM Shares") through Cowen. Upon delivery of a placement notice and subject to the terms and conditions of the ATM agreement, Cowen used its commercially reasonable efforts to sell the ATM Shares, based upon the Company's instructions. The Company had provided Cowen with customary indemnification rights, and Cowen was entitled to a commission at a fixed commission rate of up to 3.0% of the gross proceeds per Share sold. Sales of the ATM Shares under the Sales Agreement were to be made in transactions that were deemed to be "at the market offerings" as defined in Rule 415 under the Securities Act of 1933, as amended, including sales made by means of ordinary brokers' transactions, including on The NASDAQ Global Market, at market prices or as otherwise agreed with Cowen. The Company began the sale of ATM Shares in May 2014. The Company sold 14.3 million shares of common stock resulting in net proceeds of $38.6 million, which included Cowen's commission of $1.1 million and other fees of $0.3 million. The Company completed all sales under the ATM equity program in July 2014.
	In November 2013, the Company entered into the 2013 SPA with GSK and certain entities controlled by Redmile Group, LLC for the private placement of a combination of shares of common stock (the "Shares") and warrants (the "Warrants") to purchase shares of the common stock (collectively, the "Units"). Each of the investors was one of the Company's stockholders prior to consummation of these transactions. The Shares and the Units sold to the investors were offered and sold in reliance on exemptions from registration pursuant to Rule 506 of Regulation D promulgated under the Securities Act based on the nature of such investors and certain representations made to the Company. Pursuant to the 2013 SPA, Amicus agreed to issue 1.5 million Shares at $2.00 per Share to GSK and 6 million Units at $2.00 per Unit to Redmile Group, with each Unit consisting of one Share and .267 Warrants resulting in an aggregate of 6 million Shares and 1.6 million Warrants underlying the Units to be issued. Each Warrant is exercisable between July 1, 2014 and June 30, 2015 with an exercise price of $2.50, subject to certain adjustments. The Company received total proceeds of $15 million for general corporate and working capital purposes as a result of the private placement and the transaction closed in November 2013. In October 2014, GSK sold all their shares and no longer have an ownership position in the Company as of December 31, 2014.
	The Company evaluated the warrants against current accounting guidance and determined that these warrants should be accounted as a component of equity. As such, these warrants are valued at issuance date using the Black Scholes valuation model using inputs such as the underlying price of the shares issued when the warrant is exercised, volatility, risk free interest rate and expected life of the instrument. The six inputs used to determine the value of the warrants were: (1) the closing price of Amicus stock on the day of evaluation of $2.12; (2) the exercise price of the warrants of $2.50; (3) the remaining term of the warrants of 1 year; (4) the volatility of Amicus' stock for the one year term of 93.5%; (5) the annual rate of dividends of 0%; and (6) the riskless rate of return of 0.12%. The annual rate of dividends is based on the Company's historical practice of not granting dividends. The resulting Black Scholes value of the warrants was $1.0 million.
	In November 2013, in connection with its acquisition of Callidus, the Company agreed to issue an aggregate of 7.2 million shares of its common stock, par value $0.01 per share, to the former stockholders of Callidus. As of December 31, 2014, approximately 25 thousand shares remain issuable to former Callidus stockholders.
	Nonqualified Cash Deferral Plan
	In July 2014, the Board of Directors approved the Company's Deferral Plan, which provides certain key employees and members of the Board of Directors as selected by the Compensation Committee, with an opportunity to defer the receipt of such Participant's base salary, bonus and director's fees, as applicable. The Deferral Plan is intended to be a nonqualified deferred compensation plan that complies with the provisions of Section 409A of the Code.
	As of December 31, 2014, the amounts deferred under the Deferral Plan have not been invested. The investments are expected to be made in the first quarter of fiscal year 2015. Deferred compensation as of December 31, 2014 totaled approximately $0.1 million and is included in other long-term liabilities within the accompanying consolidated balance sheets. All of the investments held in the Deferral Plan will be classified as trading securities and recorded at fair value with changes in the investments' fair value recognized in the period they occur. The corresponding liability for the Deferral Plan is included in other non-current liability in the Company's consolidated balance sheets.
	Stock Option Plans
	In June 2014, the Company's stockholders approved the Amended and Restated 2007 Equity Incentive Plan (the "Plan"). The amendment to the Plan makes an additional 6 million shares of the Company's common stock available for issuance and increases the maximum number of shares within the Plan that may be issued as restricted stock, RSUs, stock grants and any other similar awards from 1.1 million to 1.5 million shares. As of December 31, 2014, awards issued under the Plan include both stock options and RSUs.
	In May 2007, the Company's Board of Directors and stockholders approved the Company's 2007 Director Option Plan (the "2007 Director Plan"). The Plan provides for the granting of restricted stock and options to purchase common stock in the Company to employees, advisors and consultants at a price to be determined by the Company's board of directors. The Plan is intended to encourage ownership of stock by employees and consultants of the Company and to provide additional incentives for them to promote the success of the Company's business. The 2007 Director Plan is intended to promote the recruiting and retention of highly qualified eligible directors and strengthen the commonality of interest between directors and stockholders by encouraging ownership of common stock of the Company. Under the provisions of each plan, no option will have a term in excess of 10 years.
	The Board of Directors, or its committee, is responsible for determining the individuals to be granted options, the number of options each individual will receive, the option price per share, and the exercise period of each option. Options granted pursuant to the Plan generally vest 25% on the first year anniversary date of grant plus an additional 1/48th for each month thereafter and may be exercised in whole or in part for 100% of the shares vested at any time after the date of grant. Options under the 2007 Director Plan may be granted to new directors upon joining the Board and vest in the same manner as options under the Plan. In addition, options are automatically granted to all directors at each annual meeting of stockholders and vest on the date of the annual meeting of stockholders of the Company in the year following the year during which the options were granted.
	As of December 31, 2014, the Company has reserved up to 6,595,880 shares for issuance under the Plan and the 2007 Director Plan.
	Stock Option Grants
	The Company adopted the fair value method of measuring stock-based compensation, which requires a public entity to measure the cost of employee services received in exchange for an award of equity instruments based upon the grant-date fair value of the award. The Company chose the "straight-line" attribution method for allocating compensation costs and recognized the fair value of each stock option on a straight-line basis over the vesting period of the related awards.
	The Company uses the Black-Scholes option pricing model when estimating the fair value for stock-based awards. Use of a valuation model requires management to make certain assumptions with respect to selected model inputs. Expected volatility was calculated based on a blended weighted average of historical information of the Company's stock and the weighted average of historical information of similar public entities for which historical information was available. The Company will continue to use a blended weighted average approach using its own historical volatility and other similar public entity volatility information until the Company's historical volatility is relevant to measure expected volatility for future option grants. The average expected life was determined using the "simplified" method of estimating the expected exercise term which is the mid-point between the vesting date and the end of the contractual term. As the Company's stock price volatility has been over 75% and it has experienced significant business transactions, the Company does not have sufficient reliable exercise data in order to justify a change in the use of the "simplified" method of estimating the expected exercise term of employee stock option grants. The risk-free interest rate is based on U.S. Treasury, zero-coupon issues with a remaining term equal to the expected life assumed at the date of grant. Forfeitures are estimated based on voluntary termination behavior, as well as a historical analysis of actual option forfeitures.
	The weighted average assumptions used in the Black-Scholes option pricing model are as follows:
		Years Ended December 31,
		2014			2013			2012
	Expected stock price volatility		81.3	%		82.0	%		77.2	%
	Risk free interest rate		1.9	%		1.3	%		0.8	%
	Expected life of options (years)		6.25			6.25			6.25
	Expected annual dividend per share	$	0.00		$	0.00		$	0.00
	The weighted average grant-date fair value per share of options granted during 2014, 2013 and 2012 were $2.12, $2.14 and $3.31, respectively.
	The following table summarizes information about stock options outstanding:
		Number of			Weighted			Weighted		Aggregate
		Shares			Average			Average		Intrinsic
					Exercise			Remaining		Value
					Price			Contractual Life
		(in thousands)								(in millions)
	Options outstanding, December 31, 2011		6,653.50		$	6.87
	Granted		2,846.60		$	5.34
	Exercised		(437.0	)	$	3.73
	Forfeited		(1,088.9	)	$	7.95
	Options outstanding, December 31, 2012		7,974.20		$	6.35
	Granted		2,481.80		$	3.04
	Exercised		—			—
	Forfeited		(1,414.9	)	$	5.01
	Options outstanding, December 31, 2013		9,041.10		$	5.65
	Granted		2,993.10		$	2.99
	Exercised		(965.6	)	$	3.8
	Forfeited		(1,047.9	)	$	5.76
	Options outstanding, December 31, 2014		10,020.70		$	5.02		6.8 years		$	36.9
	Vested and unvested expected to vest, December 31, 2014		9,441.00		$	5.13		6.7 years		$	34
	Exercisable at December 31, 2014		5,447.90		$	6.45		5.2 years		$	14
	The aggregate intrinsic value of options exercised during the years ended December 31, 2014 and 2012 was $2.8 million and $0.9 million, respectively. There were no options exercised during the year ended December 31, 2013. As of December 31, 2014, the total unrecognized compensation cost related to non-vested stock options granted was $7.7 million and is expected to be recognized over a weighted average period of 2.3 years. Cash proceeds from stock options exercised during the years ended December 31, 2014 and 2012 were $3.7 million and $1.6 million respectively.
	Restricted Stock Units
	In April 2014, the Compensation Committee made awards of RSUs to certain employees of the Company. The RSUs awarded under the Plan are generally subject to graded vesting of 50% of the RSUs on the 13th month anniversary of the grant date and the remaining 50% of the RSUs on the 20th month anniversary of the grant date, in each case, contingent on such employee's continued service on such date.
	RSUs are generally subject to forfeiture if employment terminates prior to the release of vesting restrictions. The Company expenses the cost of the RSUs, which is determined to be the fair market value of the shares of common stock underlying the RSUs at the date of grant, ratably over the period during which the vesting restrictions lapse.
	A summary of non-vested RSU activity under the Plan for the year ended December 31, 2014 is as follows:
		Number of			Weighted			Weighted			Aggregate
		Shares			Average Grant			Average			Intrinsic
					Date Fair			Remaining			Value
					Value			Years
		(in thousands)									(in millions)
	Non-vested units as of December 31, 2013		—		$	—
	Granted		975		$	2.28
	Vested		—		$	—
	Forfeited		(20	)	$	2.15
	Non-vested units as of December 31,2014		955		$	2.28			0.74		$	5.8
For the year ended December 31, 2014, there were no RSUs that vested and all non-vested units are expected to vest over their normal term. As of December 31, 2014, there was $1.1 million of total unrecognized compensation cost related to unvested RSUs with service-based vesting conditions. These costs are expected to be recognized over a weighted average period of 0.74 years.
In April 2014, the Board of Directors approved the Company's Restricted Stock Unit Deferral Plan ("the Deferred Compensation Plan"), which provides selected employees with an opportunity to defer receipt of RSUs until the first to occur of termination of the employee's employment or a date selected by the employee. Any RSUs deferred under the Deferred Compensation Plan would be fully vested once the original vesting conditions of the RSU were satisfied.
Compensation Expense Related to Equity Awards
The following table summarizes the stock-based compensation expense recognized in the statements of operations (in thousands):
	Years Ended December 31,
	2014			2013			2012
Stock compensation expense recognized in:
Research and development expense	$	2,703		$	3,583		$	3,603
General and administrative expense		3,305			2,594			2,588
Total stock compensation expense	$	6,008		$	6,177		$	6,191

Assets_and_Liabilities_Measure

Assets and Liabilities Measured at Fair Value	12 Months Ended
	Dec. 31, 2014
Assets and Liabilities Measured at Fair Value
Assets and Liabilities Measured at Fair Value
	10. Assets and Liabilities Measured at Fair Value
	The Company's financial assets and liabilities are measured at fair value and classified within the fair value hierarchy which is defined as follows:
	Level 1 — Quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.
	Level 2 — Inputs other than quoted prices in active markets that are observable for the asset or liability, either directly or indirectly.
	Level 3 — Inputs that are unobservable for the asset or liability.
	Cash, Money Market Funds and Marketable Securities
	The Company classifies its cash and money market funds within the fair value hierarchy as Level 1 as these assets are valued using quoted prices in active market for identical assets at the measurement date. The Company considers its investments in marketable securities as available for sale and classifies these assets within the fair value hierarchy as Level 2 primarily utilizing broker quotes in a non-active market for valuation of these securities. No changes in valuation techniques or inputs occurred during the year ended December 31, 2014. No transfers of assets between Level 1 and Level 2 of the fair value measurement hierarchy occurred during the year ended December 31, 2014.
	Secured Debt
	As disclosed in "— Note 16. Short Term Borrowings and Long Term Debt", the Company has a new loan and security agreement with MidCap Financial, Oxford Finance and Silicon Valley Bank, in addition to an earlier existing loan with Silicon Valley Bank. The carrying amount of the Company's borrowings approximates fair value at December 31, 2014. The Company's secured debt is classified as Level 2 and the fair value is estimated using quoted prices for similar liabilities in active markets, as well as inputs that are observable for the liability (other than quoted prices), such as interest rates that are observable at commonly quoted intervals.
	In connection with the Term Loan, as disclosed in "— Note 16. Short Term Borrowings and Long Term Debt", the Company recorded a contingent liability of approximately $0.3 million representing the fair value of a contingent payment of up to $0.4 million related to a success fee payable within six months of trigger event, with the trigger event being regulatory acceptance of NDA or MAA submission. This is effective 5 years from the closing of the Term Loan. The success fee payable to the lender was probability adjusted and discounted utilizing an appropriate discount rate and hence classified as Level 3.
	Contingent Consideration Payable
	The contingent consideration payable resulted from acquisition of Callidus, as discussed in "— Note 3. Acquisition of Callidus Biopharma, Inc." Our most recent valuation was determined using a probability-based income approach utilizing a discounted rate of 11.5%, which is a measure of the credit risk associated with settling the liability. For 2014 compared to 2013, the net increase in the fair value of this obligation was primarily due to the elapse of time of when the contingent consideration could be paid. Some of the more significant assumptions used in the valuation include (i) the probability and timing related to the achievement of certain developmental milestones and (ii) and the discount rate. The contingent consideration is revalued each reporting period. There is no assurance that any of the conditions for the milestone payments will be met.
	The contingent consideration payable has been classified as a Level 3 liability as its valuation requires substantial judgment and estimation of factors that are not currently observable in the market. If different assumptions were used for the various inputs to the valuation approach the estimated fair value could be significantly higher or lower than the fair value the Company determined. The Company may be required to record losses in future periods.
	A summary of the fair value of the Company's assets and liabilities aggregated by the level in the fair value hierarchy within which those measurements fall as of December 31, 2014 are identified in the following table (in thousands):
		Level 1		Level 2		Total
	Assets:
	Cash/money market funds	$	24,074	$	—	$	24,074
	Commercial paper		—		11,499		11,499
	Corporate debt securities		—		133,216		133,216
	Certificate of deposit		—		350		350
		$	24,074	$	145,065	$	169,139
		Level 1		Level 2		Level 3		Total
	Liabilities:
	Secured debt	$	—	$	14,350	$	—	$	14,350
	Contingent success fee payable		—		—		341		341
	Contingent consideration payable		—		—		10,700		10,700
		$	—	$	14,350	$	11,041	$	25,391
	A summary of the fair value of the Company's assets and liabilities aggregated by the level in the fair value hierarchy within which those measurements fall as of December 31, 2013 are identified in the following table (in thousands):
		Level 1		Level 2		Total
	Assets:
	Cash/money market funds	$	43,640	$	—	$	43,640
	Commercial paper		—		7,198		7,198
	Corporate debt securities		—		30,812		30,812
	Certificate of deposit		—		350		350
		$	43,640	$	38,360	$	82,000
		Level 1		Level 2		Level 3		Total
	Liabilities:
	Secured debt	$	—	$	14,473	$	—	$	14,473
	Contingent success fee payable		—		—		264		264
	Contingent consideration payable		—		—		10,600		10,600
		$	—	$	14,473		10,864		25,337
	The change in the fair value of Level 3 liabilities at December 31, 2014 was an increase of $0.2 million due to the increase in fair value of contingent consideration payable of $0.1 million and contingent success fee payable of $77 thousand. The change in the fair value of Level 3 liabilities at December 31, 2013 was an increase of $10.0 million due to the addition of contingent consideration payable of $10.6 million and contingent success fee payable of $0.3 million, offset by the decrease in the fair value of the warrant liability of $0.9 million.

401k_Plan

401(k) Plan	12 Months Ended
	Dec. 31, 2014
401(k) Plan
401(k) Plan
	11. 401(k) Plan
	The Company has a 401(k) plan (the "401(k) Plan") covering all eligible employees and provides for a company match of up to 5% of salary and bonus paid during the year. In 2013, the Company changed the vesting policy whereby the match vests immediately upon enrollment. The Company's total contribution to the 401(k) Plan was $0.6 million, $0.7 million and $0.7 million for the years ended December 31, 2014, 2013 and 2012, respectively.

Leases

Leases	12 Months Ended
	Dec. 31, 2014
Leases
Leases
	12. Leases
	Operating Leases
	The Company leases approximately 73,646 square feet of laboratory and office space in Cranbury, New Jersey. The lease will expire in March 2019 and may be extended by the Company for two additional five-year periods. The Company also has a lease for its laboratory and office space in San Diego, CA, which will expire in September 2016. The San Diego, CA, location was closed as of December 31, 2013, however lease payments will continue to be made until end of lease term. See "— Note 17. Restructuring Charges" for more information. Rent expenses for the Company's facilities are recognized over the term of the lease. The Company recognizes rent starting when possession of the facility is taken from the landlord. When a lease contains a predetermined fixed escalation of the minimum rent, the Company recognizes the related rent expense on a straight-line basis and records the difference between the recognized rental expense and the amounts payable under the lease as deferred rent liability. Tenant leasehold improvement allowances are reflected in accrued expenses on the consolidated balance sheets and are amortized as a reduction to rent expense in the statement of operations over the term of the lease.
	At December 31, 2014, aggregate annual future minimum lease payments, net of income from subleases, under these leases are as follows:
	(in thousands)	2015			2016			2017		2018		2019 and beyond		Total
	Minimum lease payments	$	2,033		$	2,039		$	1,769	$	1,778	$	297	$	7,916
	Less: income from sublease		(210	)		(180	)		—		—		—		(390	)
	Net minimum lease payments	$	1,823		$	1,859		$	1,769	$	1,778	$	297	$	7,526
	Rent expense for the years ended December 31, 2014, 2013 and 2012 were $2.4 million, $2.6 million and $2.6 million respectively.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Taxes
Income Taxes
	13. Income Taxes
	In June 2006, the FASB issued a single model to address accounting for uncertainty in tax positions. The model clarifies the accounting for income taxes, by prescribing a minimum recognition threshold a tax position is required to meet before being recognized in the financial statements. It also provides guidance on de-recognition, measurement, and classification of amounts relating to uncertain tax positions, accounting for and disclosure of interest and penalties, accounting in interim periods and disclosures required. The Company adopted the FASB requirements as of January 1, 2007 and determined that it did not have a material impact on the Company's financial position and results of operations. The Company did not recognize interest or penalties related to income tax during the period ended December 31, 2014 and did not accrue for interest or penalties as of December 31, 2014. The Company does not have an accrual for uncertain tax positions as of December 31, 2014. Tax returns for all years 2008 and thereafter are subject to future examination by tax authorities.
	Deferred income taxes reflect the net effect of temporary difference between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The significant components of the deferred tax assets and liabilities are as follows (in thousands):
		For Years Ended
		December 31,
		2014			2013
	Current deferred tax asset
	Non-cash stock issue	$	8,990		$	8,172
	Others		2,023			1,343
		$	11,013			9,515
	Non-current deferred tax assets
	Amortization/depreciation		2,910			3,068
	Research tax credit		14,288			13,680
	Net operating loss carry forwards		105,274			79,984
	Deferred revenue		14,626			14,649
	Others		324			682
	Gross deferred tax assets		148,435			121,578
	Deferred tax liability related to business acquisition		(9,186	)		(9,186	)
	Total net deferred tax asset		139,249			112,392
	Less valuation allowance		(148,435	)		(121,578	)
	Net deferred tax assets (liability)	$	(9,186	)	$	(9,186	)
	The Company records a valuation allowance for temporary differences for which it is more likely than not that the Company will not receive future tax benefits. At December 31, 2013, and 2014, the Company recorded valuation allowances of $121.6 million and $148.4 million, respectively, representing an increase in the valuation allowance of $26.3 million in 2013 and an increase of $26.8 million in 2014, due to the uncertainty regarding the realization of such deferred tax assets, to offset the benefits of net operating losses generated during those years.
	As of December 31, 2014, the Company had federal and state net operating loss carry forwards ("NOLs") of approximately $268.5 million and $235.5 million, respectively. The federal carry forward will expire in 2028 through 2034. Most of the state carry forwards generated prior to 2009 began to expire in 2012 and will continue to expire through 2015. The remaining state carry forwards including those generated in 2009 through 2012 will expire in 2029 through 2034 due to a change in the New Jersey state law regarding the net operating loss carry forward period. Utilization of NOLs may be subject to a substantial limitation pursuant to Section 382 of the Code as well as similar state statutes in the event of an ownership change. Such ownership changes have occurred in the past, and could occur again in the future As a result of these ownership changes, Section 382 places an annual limitation on the amount of NOLs that can be utilized to offset future taxable income each year, which is based on the value of the company at the change date. This limitation could result in expiration of those carry forwards before utilization. In general, an ownership change, as defined by Section 382, results from transactions that increase the ownership of certain stockholders or public groups in the stock of a corporation by more than 50 percentage points over a three year period. The Company completed a detailed study of its cumulative ownership changes for 2014 and determined that there was an ownership change in excess of 50% in October of 2014. Based on the value of the Company at the change date, the limitation amount is estimated to be sufficient to permit the utilization of up to approximately $397 million over the next 20 years, which exceeds the total of the Company's NOLs through December 31, 2014. Therefore, there was no need to write down the gross amount of the deferred tax asset related to the Company's federal NOLs. A tax benefit of $0.2 million associated with the exercise of stock options will be recorded in additional paid-in capital when the associated net operating loss is recognized.
	A reconciliation of the statutory tax rates and the effective tax rates for the years ended December 31, 2012, 2013 and 2014 are as follows:
		Years Ended
		December 31,
		2014			2013			2012
	Statutory rate		(34	)%		(34	)%		(34	)%
	State taxes, net of federal benefit		(4	)		(5	)		(3	)
	Permanent adjustments		1			(1	)		(1	)
	R&D credit		(4	)		(3	)		(8	)
	Other		1			—			1
	Valuation allowance		38			37			38
	Net		(2	)%		(6	)%		(6	)%
	The Company recognized a tax benefit of $3.2 million, $3.5 million and $1.1 million in connection with the sale of net operating losses and research and development credits in the New Jersey Transfer Program for the years ended December 31, 2012, 2013 and 2014, respectively.

Licenses

Licenses	12 Months Ended
	Dec. 31, 2014
Licenses
Licenses
	14. Licenses
	The Company acquired rights to develop and commercialize its product candidates through licenses granted by various parties. The following summarizes the Company's material rights and obligations under those licenses:
	GSK — For discussion of the royalties and milestone payments potentially due to GSK, see "— Note 15. Collaborative Agreements."
	Mt. Sinai School of Medicine of New York University ("MSSM") — The Company acquired exclusive worldwide patent rights to develop and commercialize migalastat and other pharmacological chaperones for the prevention or treatment of human diseases or clinical conditions by increasing the activity of wild-type and mutant enzymes pursuant to a license agreement with MSSM. This agreement expires upon expiration of the last of the licensed patent rights, which will be in 2019, subject to any patent term extension that may be granted, or 2024 if the Company develops a product for combination therapy (pharmacological chaperone plus ERT) and a patent issues from the pending application covering combination therapy, subject to any patent term extension that may be granted. Under this agreement, to date the Company has paid no upfront or annual license fees and has no milestone or future payments other than royalties on net sales. In 2008, the Company amended and restated its license agreement with MSSM which consolidated previous amendments into a single agreement, clarified the portion of royalties and milestone payments the Company received from collaboration agreements that were payable to MSSM, and provided the Company with the sole right to control the prosecution of patent rights described in the amended and restated license agreement. Payments to MSSM are classified as research and development expenses in the Company's financial statements.
	Under its license agreements, if the Company owes royalties on net sales for one of its products to more than one of the above licensors, then it has the right to reduce the royalties owed to one licensor for royalties paid to another. The amount of royalties to be offset is generally limited in each license and can vary under each agreement. For migalastat, the Company will owe royalties only to MSSM and will owe no milestone payments.
	The Company's rights with respect to these agreements to develop and commercialize migalastat may terminate, in whole or in part, if the Company fails to meet certain development or commercialization requirements or if the Company does not meet its obligations to make royalty payments.

Collaborative_Agreements

Collaborative Agreements	12 Months Ended
	Dec. 31, 2014
Collaborative Agreements
Collaborative Agreements
	15. Collaborative Agreements
	GSK
	In November 2013, Amicus entered into the Revised Agreement with GSK, pursuant to which Amicus has obtained global rights to develop and commercialize migalastat as a monotherapy and in combination with ERT for Fabry disease. The Revised Agreement amends and replaces in its entirety the Expanded Agreement entered into between Amicus and GSK in July 2012. Under the terms of the Revised Agreement, there was no upfront payment from Amicus to GSK. For migalastat monotherapy, GSK is eligible to receive post-approval and sales-based milestones up to $40 million, as well as tiered royalties in the mid-teens in eight major markets outside the U.S.
	Under the terms of the Revised Agreement, GSK will no longer jointly fund development costs for all formulations of migalastat.
	In evaluating the impact of both the Expanded Collaboration Agreement and the Revised Agreement, the Company applied the accounting guidance regarding the impact of potential future payments it may make in its role as a vendor (i.e., Amicus) to its customer (i.e., GSK) and evaluated if these potential future payments could be a reduction of revenue from GSK. If the potential future payments to GSK are as follows:
	•	a payment for an identifiable benefit, and
	•	the identifiable benefit is separable from the existing relationship between the Company and GSK, and
	•	the identifiable benefit can be obtained from a party other than GSK, and
	•	the Company can reasonably estimate the fair value of the identifiable benefit,
	then the potential future payments would be treated separately from the collaboration and research revenue. However, if all these criteria are not satisfied, then the potential future payments are treated as a reduction of revenue.
	Accordingly, the Company did not believe that, for accounting purposes, the new U.S. licensing rights to migalastat obtained from GSK under the Expanded Collaboration Agreement, nor the ex U.S. licensing rights to migalastat obtained from GSK under the Revised Agreement, represented a separate, identifiable benefit from the licenses in the Original Collaboration Agreement entered into between Amicus and GSK in 2010. The contingent amounts payable to GSK were not sufficiently separable from GSK's original license and the research and development reimbursements such that Amicus could not have entered into a similar exchange transaction with another party. Additionally, the Company cannot reasonably estimate the fair value of the worldwide licensing rights to migalastat.
	The Company determined that the potential future payments to GSK would be treated as a reduction of revenue and that the total amount of revenue to be received under the arrangement is no longer fixed or determinable as the contingent milestone payments are subject to significant uncertainty.
	As a result, the Company no longer recognized any of the upfront license fees and premiums on the equity purchase from GSK until such time as the arrangement consideration becomes fixed or determinable, because an indeterminable amount may ultimately be payable back to GSK. These amounts (the balance of the unrecognized upfront license fee and the premium on the equity purchases) are classified as deferred reimbursements on the balance sheet.
	The recognition of Research Revenue was also affected by the determination that the overall total arrangement consideration was no longer fixed and determinable, despite the fact that the research activities continued and that the research expense reimbursements by GSK to Amicus were received as the research activities related to the reimbursement had been completed. Therefore the research reimbursements from GSK were recorded as deferred reimbursements on the balance sheet and would not recognized until the total arrangement consideration becomes fixed and determinable.
	As a result, all revenue recognition was suspended until the total arrangement consideration would become fixed and determinable. In addition, future milestone payments made by the Company will be applied against the balance of this deferred reimbursements account. In the third quarter of 2013, the Company paid GSK a pass-through milestone payment of $0.8 million in connection with the development of the Co-formulated product. This payment was reflected as a reduction of the deferred reimbursements in the Consolidated Balance Sheet as of December 31, 2013.
	Revenue recognition for research expense reimbursements, the original upfront license fee, and the equity premiums will resume once the total arrangement consideration becomes fixed and determinable which will occur when the balance of the deferred reimbursements account is sufficient to cover all the remaining contingent milestone payments.
	Biogen
	In September 2013, the Company entered into a license and collaboration agreement (the "Biogen Agreement") with Biogen to discover, develop and commercialize novel small molecules for the treatment of Parkinson's disease. Under terms of the multi-year agreement, the Company and Biogen will collaborate in the discovery of a new class of small molecules that target the GCase enzyme, for further development and commercialization by Biogen. Biogen was responsible for funding all discovery, development, and commercialization activities. In addition the Company was reimbursed for all full-time employees working on the project as part of a cost sharing arrangement. The Company was also eligible to receive development and regulatory milestones, as well as modest royalties in global net sales.
	In accordance with the revenue recognition guidance related to reimbursement of research and development expenses, the Company identified all deliverables at the inception of the agreement. As the Company has not commenced its planned principal operations (i.e. selling commercial products) the Company is only performing development of its compounds, and therefore, development activities are part of the Company's ongoing central operations. Additionally, the Company has the following accounting policies:
	•	Research and development expenses related to a collaboration agreement will be recorded on a gross basis in the income statement and not presented net of any reimbursement received from a collaboration agreement; and
	•	The reimbursement of research and development expenses from a collaborator will be recognized in the income statement as "Research Revenue" for the period in which the research activity occurred.
	As of December 31, 2014, the Company recognized $1.2 million in Research Revenue for work performed under the cost sharing arrangement of the Biogen Agreement.
	The Company evaluated the contingent milestones included in the Biogen Agreement at the inception of the Biogen Agreement and determined that the contingent milestones are substantive milestones and would be recognized as revenue in the period that the milestone was achieved. The Company determined that the research based milestones are commensurate with the enhanced value of each delivered item as a result of the Company's specific performance to achieve the milestones. The research based milestones would relate to past performances when achieved and are reasonable relative to the other payment terms within the Biogen Agreement, including the cost sharing arrangement.
	In September 2014, the Company and Biogen concluded their research collaboration. The Company's most advanced Parkinson's candidate is AT3375, which was developed outside the collaboration and is wholly-owned by the Company.

ShortTerm_Borrowings_and_LongT

Short-Term Borrowings and Long-Term Debt	12 Months Ended
	Dec. 31, 2014
Short-Term Borrowings and Long-Term Debt
Short-Term Borrowings and Long-Term Debt
	16. Short-Term Borrowings and Long-Term Debt
	In December 2013, the Company entered into a credit and security agreement with a lending syndicate consisting of MidCap Funding III, LLC, Oxford Finance LLC, and Silicon Valley Bank ("SVB") which provides an aggregate of $25 million (the "Term Loan"). The Company drew $15 million of the aggregate principal amount of the Term Loan at the end of December 2013 (the "First Tranche") and did not draw the additional $10 million that was available through the end of the fourth quarter of 2014. The principal outstanding balance of the First Tranche bears interest at a rate per annum fixed at 8.5%. The Company made interest-only payments on the Term Loan beginning January 1, 2014 and will continue through April 1, 2015, after which the Company will repay the aggregate principal outstanding balance of the Term Loan in 33 equal monthly installments of principal, plus accrued interest at the applicable rate. The Term Loan matures on December 27, 2017. At December 31, 2014, the total principal amount due under the Term Loan was $15 million.
	In connection with the Term Loan, the Company recorded a debt discount of $0.8 million at December 31, 2013 which consists of payments to be made and a contingent payable to the lenders. These payments include a debt facility fee of $0.1 million which was paid on the date of the First Tranche, $0.4 million exit fee that will be payable upon repayment of the term loan and $0.3 million representing the fair value of a contingent payment of up to $0.4 million related to a success fee payable within six months of trigger event, with the trigger event being regulatory acceptance of NDA or MAA submission. This is effective 5 years from the closing of the Term Loan. The success fee payable to the lender was probability adjusted and discounted utilizing an appropriate discount rate and is shown as a current liability on the Company's consolidated balance sheet.
	In February 2012, the Company borrowed approximately $1.0 million from a loan and security agreement (the "2011 Loan Agreement") with SVB which was to be repaid over the following 2.5 years. The 2011 Loan Agreement contains financial covenants and the Company has at all times been in compliance with these covenants. As of December 31, 2014, the 2011 Loan Agreement has been fully repaid and there is no amount currently due.
	The carrying amount of the Company's borrowings approximates fair value at December 31, 2014.
	The remaining future minimum payments of principal due as of December 31, 2014 are as follows (in thousands):
	Years ending December 31:
	2015	$	4,035
	2016		5,444
	2017		5,521
	2018		—
	2019 and beyond		—
	Total principal obligation		15,000
	Less short-term portion, net of short term debt discount of $195		(3,840	)
	Long-term portion		11,160
	Less debt discount		(650	)
	Long term portion, net of debt discount	$	10,510

Restructuring_Charges

Restructuring Charges	12 Months Ended
	Dec. 31, 2014
Restructuring Charges
Restructuring Charges
	17. Restructuring Charges
	In November 2013, the Company announced a work-force reduction of approximately 14 percent, or 15 employees, as a part of a corporate restructuring. This measure was intended to reduce costs and to align the Company's resources with its key strategic priorities.
	In December 2013, the Company initiated and completed a facilities consolidation effort, closing one of its leased locations in San Diego, CA. The Company recorded a total charge of $2.0 million during the fourth quarter of 2013 which included $1.2 million for employment termination costs payable and a facilities consolidation charge of $0.8 million consisting of lease payments of $0.7 million related to the net present value of the net future minimum lease payments at the cease-use date and the write-down of the net book value of the fixed assets in the vacated building of $0.1 million. At December 31, 2014, all of the restructuring charges related to employment termination costs were paid.
	The following table summarizes the restructuring charges and utilization for the year ended December 31, 2014 (in thousands):
		Balance as of		Charges		Cash Payments			Adjustments			Balance as of
		December 31,										December 31,
		2013										2014
	Employment termination costs	$	1,139	$	—	$	(1,139	)	$	—		$	—
	Facilities consolidation		703		—		(357	)		(63	)		283
	Total	$	1,842	$	—	$	(1,496	)	$	(63	)	$	283
	The lease charges will be paid over the remaining lease term which expires in September 2016.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events
Subsequent Events
	18. Subsequent Events
	The Company evaluated events that occurred subsequent to December 31, 2014 and there were no material recognized or non-recognized subsequent events during this period.

Earnings_per_Share

Earnings per Share	12 Months Ended
	Dec. 31, 2014
Earnings per Share
Earnings per Share
	19. Earnings per Share
	The following table provides a reconciliation of the numerator and denominator used in computing basic and diluted net loss attributable to common stockholders per common share (in thousands except share amounts):
		Years Ended December 31,
		2014			2013			2012
	Historical
	Numerator:
	Net loss attributable to common stockholders	$	(68,926	)	$	(59,633	)	$	(48,785	)
	Denominator:
	Weighted average common shares outstanding — basic and diluted		74,444,157			51,286,059			45,565,217
	Dilutive common stock equivalents would include the dilutive effect of common stock options, restricted stock units and warrants for common stock equivalents. Potentially dilutive common stock equivalents were excluded from the diluted earnings per share denominator for all periods because of their anti-dilutive effect. The table below presents potential shares of common stock that were excluded from the computation as they were anti-dilutive using the treasury stock method (in thousands):
		Year ended December 31,
		2014			2013			2012
	Options to purchase common stock		10,021			9,041			7,974
	Outstanding warrants, convertible to common stock		1,600			3,004			1,405
	Unvested restricted stock units		955			—			—
	Total number of potentially issuable shares		12,576			12,045			9,379

Selected_Quarterly_Financial_D

Selected Quarterly Financial Data (Unaudited - in thousands except per share data)	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Financial Data (Unaudited - in thousands except per share data)
Selected Quarterly Financial Data (Unaudited - in thousands except per share data)
	20. Selected Quarterly Financial Data (Unaudited — in thousands except per share data)
			Quarters Ended
			March 31			June 30			September 30			December 31
	2014
	Net loss		$	(15,943	)	$	(14,614	)	$	(17,149	)	$	(21,220	)
	Basic and diluted net loss per common share (1)			(0.25	)		(0.22	)		(0.22	)		(0.24	)
	2013
	Net loss		$	(17,458	)	$	(15,349	)	$	(14,589	)	$	(12,237	)
	Basic and diluted net loss per common share (1)			(0.35	)		(0.31	)		(0.29	)		(0.22	)
	-1	Per common share amounts for the quarters and full years have been calculated separately. Accordingly, quarterly amounts do not add to the annual amounts because of differences on the weighted-average common shares outstanding during each period principally due to the effect of the Company issuing shares of its common stock during the year.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation
	The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles ("U.S.GAAP") and include all adjustments necessary for the fair presentation of the Company's financial position for the periods presented.
Consolidation	Consolidation
	The financial statements include the accounts of Amicus Therapeutics, Inc. and its wholly owned subsidiaries, Amicus Therapeutics UK Limited and Callidus Biopharma, Inc. All significant intercompany transactions and balances are eliminated in consolidation. These subsidiaries are not material to the overall financial statements of the Company.
Use of Estimates	Use of Estimates
	The preparation of financial statements in conformity with U.S.GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates.
Cash, Money Market Funds, and Marketable Securities	Cash, Money Market Funds, and Marketable Securities
	The Company considers all highly liquid investments purchased with a maturity of three months or less at the date of acquisition, to be cash equivalents.
	Marketable securities consist of fixed income investments with a maturity of greater than three months and other highly liquid investments that can be readily purchased or sold using established markets. These investments are classified as available-for-sale and are reported at fair value on the Company's balance sheet. Unrealized holding gains and losses are reported within comprehensive income/ (loss) in the statements of comprehensive loss. Fair value is based on available market information including quoted market prices, broker or dealer quotations or other observable inputs. See "— Note 6. Cash, Money Market Funds and Marketable Securities", for a summary of available-for-sale securities as of December 31, 2014 and 2013.
Concentration of Credit Risk	Concentration of Credit Risk
	The Company's financial instruments that are exposed to concentration of credit risk consist primarily of cash and cash equivalents and marketable securities. The Company maintains its cash and cash equivalents in bank accounts, which, at times, exceed federally insured limits. The Company invests its marketable securities in high-quality commercial financial instruments. The Company has not recognized any losses from credit risks on such accounts during any of the periods presented. The Company believes it is not exposed to significant credit risk on cash and cash equivalents or its marketable securities.
Property and Equipment	Property and Equipment
	Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation is calculated over the estimated useful lives of the respective assets, which range from three to five years, or the lesser of the related initial term of the lease or useful life for leasehold improvements. Assets under capital leases are amortized over the terms of the related leases or their estimated useful lives, whichever is shorter.
	The initial cost of property and equipment consists of its purchase price and any directly attributable costs of bringing the asset to its working condition and location for its intended use. Expenditures incurred after the fixed assets have been put into operation, such as repairs and maintenance, are charged to income in the period in which the costs are incurred. Major replacements, improvements and additions are capitalized in accordance with Company policy.
Revenue Recognition	Revenue Recognition
	The Company recognizes revenue when amounts are realized or realizable and earned. Revenue is considered realizable and earned when the following criteria are met: (1) persuasive evidence of an arrangement exists; (2) delivery has occurred or services have been rendered; (3) the price is fixed or determinable; and (4) collection of the amounts due are reasonably assured.
	In multiple element arrangements, revenue is allocated to each separate unit of accounting and each deliverable in an arrangement is evaluated to determine whether it represents separate units of accounting. A deliverable constitutes a separate unit of accounting when it has standalone value and there is no general right of return for the delivered elements. In instances when the aforementioned criteria are not met, the deliverable is combined with the undelivered elements and the allocation of the arrangement consideration and revenue recognition is determined for the combined unit as a single unit of accounting. Allocation of the consideration is determined at arrangement inception on the basis of each unit's relative selling price. In instances where there is determined to be a single unit of accounting, the total consideration is applied as revenue for the single unit of accounting and is recognized over the period of inception through the date where the last deliverable within the single unit of accounting is expected to be delivered.
	The Company's current revenue recognition policies, provide that, when a collaboration arrangement contains multiple deliverables, such as license and research and development services, the Company allocates revenue to each separate unit of accounting based on a selling price hierarchy. The selling price hierarchy for a deliverable is based on (i) its vendor specific objective evidence ("VSOE") if available, (ii) third party evidence ("TPE") if VSOE is not available, or (iii) best estimated selling price ("BESP") if neither VSOE nor TPE is available. The Company would establish the VSOE of selling price using the price charged for a deliverable when sold separately. The TPE of selling price would be established by evaluating largely similar and interchangeable competitor products or services in standalone sales to similarly situated customers. The BESP would be established considering internal factors such as an internal pricing analysis or an income approach using a discounted cash flow model.
	The Company also considers the impact of potential future payments it makes in its role as a vendor to its customers and evaluates if these potential future payments could be a reduction of revenue from that customer. If the potential future payments to the customer are:
	•	a payment for an identifiable benefit; and
	•	the identifiable benefit is separable from the existing relationship between the Company and its customer; and
	•	the identifiable benefit can be obtained from a party other than the customer; and
	•	the Company can reasonably estimate the fair value of the identifiable benefit
	then the payments are accounted for separate from the revenue received from that customer. If, however, all these criteria are not satisfied, then the payments are treated as a reduction of revenue from that customer.
	If the Company determines that any potential future payments to its customers are to be considered as a reduction of revenue, it must evaluate if the total amount of revenue to be received under the arrangement is fixed and determinable. If the total amount of revenue is not fixed and determinable due to the uncertain nature of the potential future payments to the customer, then any customer payments cannot be recognized as revenue until the total arrangement consideration becomes fixed and determinable.
	The reimbursements for research and development costs under collaboration agreements that meet the criteria for revenue recognition are included in Research Revenue and the costs associated with these reimbursable amounts are included in research and development expenses.
	In order to determine the revenue recognition for contingent milestones, the Company evaluates the contingent milestones using the criteria as provided by the Financial Accounting Standards Boards ("FASB") guidance on the milestone method of revenue recognition at the inception of a collaboration agreement. The criteria requires that (i) the Company determines if the milestone is commensurate with either its performance to achieve the milestone or the enhancement of value resulting from the Company's activities to achieve the milestone, (ii) the milestone be related to past performance, and (iii) the milestone be reasonable relative to all deliverable and payment terms of the collaboration arrangement. If these criteria are met then the contingent milestones can be considered as substantive milestones and will be recognized as revenue in the period that the milestone is achieved.
Fair Value Measurements	Fair Value Measurements
	The Company records certain asset and liability balances under the fair value measurements as defined by the FASB guidance. Current FASB fair value guidance emphasizes that fair value is a market-based measurement, not an entity-specific measurement. Therefore, a fair value measurement should be determined based on the assumptions that market participants would use in pricing the asset or liability. As a basis for considering market participant assumptions in fair value measurements, current FASB guidance establishes a fair value hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity (observable inputs that are classified within Levels 1 and 2 of the hierarchy) and the reporting entity's own assumptions that market participants assumptions would use in pricing assets or liabilities (unobservable inputs classified within Level 3 of the hierarchy).
	Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at measurement date. Level 2 inputs are inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs may include quoted prices for similar assets and liabilities in active markets, as well as inputs that are observable for the asset or liability (other than quoted prices), such as interest rates, foreign exchange rates, and yield curves that are observable at commonly quoted intervals. Level 3 inputs are unobservable inputs for the asset or liability, which is typically based on an entity's own assumptions, as there is little, if any, related market activity. In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety. The Company's assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset or liability.
Research and Development Costs	Research and Development Costs
	Research and development costs are expensed as incurred. Research and development expense consists primarily of costs related to personnel, including salaries and other personnel related expenses, consulting fees and the cost of facilities and support services used in drug development. Assets acquired that are used for research and development and have no future alternative use are expensed as in-process research and development.
Interest Income and Interest Expense	Interest Income and Interest Expense
	Interest income consists of interest earned on the Company's cash and cash equivalents and marketable securities. Interest expense consists of interest incurred on capital leases and secured debt.
Income Taxes	Income Taxes
	The Company accounts for income taxes under the liability method. Under this method deferred income tax liabilities and assets are determined based on the difference between the financial statement carrying amounts and tax basis of assets and liabilities and for operating losses and tax credit carry forwards, using enacted tax rates in effect in the years in which the differences are expected to reverse. A valuation allowance is recorded if it is "more likely than not" that a portion or all of a deferred tax asset will not be realized.
Other Comprehensive Income/ (Loss)	Other Comprehensive Income/ (Loss)
	Components of other comprehensive income/ (loss) include unrealized gains and losses on available-for-sale securities and are included in the statements of comprehensive loss.
Leases	Leases
	In the ordinary course of business, the Company enters into lease agreements for office space as well as leases for certain property and equipment. The leases have varying terms and expirations and have provisions to extend or renew the lease agreement, among other terms and conditions, as negotiated. Once the agreement is executed, the lease is assessed to determine whether the lease qualifies as a capital or operating lease.
	When a non-cancelable operating lease includes any fixed escalation clauses and lease incentives for rent holidays or build-out contributions, rent expense is recognized on a straight-line basis over the initial term of the lease. The excess between the average rental amount charged to expense and amounts payable under the lease is recorded in accrued expenses.
Nonqualified Cash Deferral Plan	Nonqualified Cash Deferral Plan
	In July 2014, the Board of Directors approved the Company's Cash Deferral Plan (the "Deferral Plan"), which provides certain key employees and members of the Board of Directors as selected by the Compensation Committee of the Board of Directors of the Company (the "Compensation Committee"), with an opportunity to defer the receipt of such Participant's base salary, bonus and director's fees, as applicable. The Deferral Plan is intended to be a nonqualified deferred compensation plan that complies with the provisions of Section 409A of the Internal Revenue Code (the "Code").
	As of December 31, 2014, the amounts deferred under the Deferral Plan have not been invested. The investments are expected to be made in the first quarter of fiscal year 2015. All of the investments held in the Deferral Plan will be classified as trading securities and recorded at fair value with changes in the investments' fair value recognized as earnings in the period they occur. The corresponding liability for the Deferral Plan is included in other non-current liability in our consolidated balance sheets.
Equity Incentive Plan	Equity Incentive Plan
	In June 2014, our stockholders approved the Amended and Restated 2007 Equity Incentive Plan (the "Plan"). The amendment to the Plan makes an additional 6.0 million shares of our common stock available for issuance and increases the maximum number of shares within the Plan that may be issued as restricted stock, restricted stock units ("RSUs"), stock grants and any other similar awards from 1.1 million to 1.5 million shares. As of December 31, 2014, awards issued under the Plan include both stock options and RSUs.
Stock-Based Compensation	Stock-Based Compensation
	At December 31, 2014, the Company had three stock-based employee compensation plans, which are described more fully in "— Note 9. Stockholders' Equity." The Company applies the fair value method of measuring stock-based compensation, which requires a public entity to measure the cost of employee services received in exchange for an award of equity instruments based on the grant-date fair value of the award.
Loss per Common Share	Loss per Common Share
	The Company calculates net loss per share as a measurement of the Company's performance while giving effect to all dilutive potential common shares that were outstanding during the reporting period. The Company had a net loss for all periods presented; accordingly, the inclusion of common stock options, unvested restricted stock units ("RSUs") and warrants would be anti-dilutive. Therefore, the weighted average shares used to calculate both basic and diluted earnings per share are the same. See "— Note 19. Earnings per Share" for further discussion on net loss per share.
Dividends	Dividends
	The Company has not paid cash dividends on its capital stock to date. The Company currently intends to retain its future earnings, if any, to fund the development and growth of the business and does not foresee payment of a dividend in any upcoming fiscal period.
Segment Information	Segment Information
	The Company currently operates in one business segment focusing on the development and commercialization of small molecule, orally administered therapies to treat a range of human genetic diseases. The Company is not organized by market and is managed and operated as one business. A single management team reports to the chief operating decision maker who comprehensively manages the entire business. The Company does not operate any separate lines of business or separate business entities with respect to its products. Accordingly, the Company does not accumulate discrete financial information with respect to separate service lines and does not have separately reportable segments.
Business Combinations	Business Combinations
	The Company allocates the purchase price of acquired businesses to the tangible and intangible assets acquired and liabilities assumed based upon their estimated fair values on the acquisition date. The purchase price allocation process requires management to make significant estimates and assumptions, especially at the acquisition date with respect to intangible assets and in-process research and development ("IPR&D"). In connection with the purchase price allocations for acquisitions, the Company estimates the fair value of contingent payments utilizing a probability-based income approach inclusive of an estimated discount rate.
Contingent Consideration Payable	Contingent Consideration Payable
	The Company determines the fair value of contingent acquisition consideration payable on the acquisition date using a probability-based income approach utilizing an appropriate discount rate. Contingent acquisition consideration payable is shown as a non-current liability on the Company's consolidated balance sheets. Changes in the fair value of the contingent acquisition consideration payable will be determined each period end and recorded on the consolidated statements of operations.
Intangible Assets and Goodwill	Intangible Assets and Goodwill
	The Company records goodwill in a business combination when the total consideration exceeds the fair value of the net tangible and identifiable intangible assets acquired. Purchased IPR&D is accounted for as an indefinite lived intangible asset until the underlying project is completed, at which point the intangible asset will be accounted for as a definite lived intangible asset, or abandoned, at which point the intangible asset will be written off or partially impaired. Goodwill and indefinite lived intangible assets are assessed annually for impairment and whenever events or circumstances indicate that the carrying amount of an asset may not be recoverable. If it is determined that the full carrying amount of an asset is not recoverable, an impairment loss is recorded in the amount by which the carrying amount of the asset exceeds its fair value.
Restructuring	Restructuring
	Restructuring charges are recognized as a result of actions to streamline operations and rationalize manufacturing facilities. Judgment is used when estimating the impact of restructuring plans, including future termination benefits and other exit costs to be incurred when the actions take place. Actual results could vary from these estimates.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In November 2014, the FASB issued ASU 2014-17, Business Combinations (Topic 805): Pushdown Accounting which provides an acquired entity with the option to apply pushdown accounting in its separate financial statements upon occurrence of an event in which an acquirer obtains control of the acquired entity. The ASU is effective on November 18, 2014. After the effective date, an acquired entity can make an election to apply the guidance to future change-in-control events or to its most recent change-in-control event. However, if the financial statements for the period in which the most recent change-in-control event occurred already have been issued or made available to be issued, the application of this guidance would be a change in accounting principle. The Company is currently assessing the impact that this standard will have on its consolidated financial statements.
	In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements-Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern, which defines management's responsibility to assess an entity's ability to continue as a going concern, and to provide related footnote disclosures if there is substantial doubt about its ability to continue as a going concern. The pronouncement is effective for annual reporting periods ending after December 15, 2016 with early adoption permitted. The adoption of this guidance is not expected to have a significant impact on the Company's consolidated financial state.
	In June 2014, the FASB issued ASU 2014-10 that removes the definition of development stage entity from the accounting standards codification, thereby removing the financial reporting distinction between development stage entities and other reporting entities from U.S. GAAP. In addition, the ASU eliminates the requirements for development stage entities to (i) present inception-to-date information in the statement of income, cash flow and stockholders' equity, (ii) label the financial statements as those of a development stage entity, (iii) disclose a description of the development stage activities in which the entity is engaged, and (iv) disclose in the first year in which the entity is no longer a development stage entity that in prior years it had been in the development stage. The Company has applied the ASU to its financial statements as of June 30, 2014.
	In May 2014, FASB issued ASU 2014-09, Revenue From Contracts With Customers, that outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. The ASU is based on the principle that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The ASU also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to fulfill a contract. Entities have the option of using either a full retrospective or a modified retrospective approach for the adoption of the new standard. The ASU becomes effective for the Company at the beginning of its 2017 fiscal year; early adoption is not permitted. The Company is currently assessing the impact that this standard will have on its consolidated financial statements.

Acquisition_of_Callidus_Biopha1

Acquisition of Callidus Biopharma, Inc. (Tables)	12 Months Ended
	Dec. 31, 2014
Acquisition of Callidus Biopharma, Inc.
Schedule of allocation of purchase consideration, including the contingent acquisition consideration payable, based on fair value
		(in thousands)
	Upfront equity payments	$	15,000
	Contingent acquisition consideration payable		10,600
	Total consideration		25,600
	Cash and cash equivalents		34
	Property, plant and equipment		173
	Intangible assets — IPR&D		23,000
	Total identifiable assets acquired	$	23,207
	Accounts payable		(34	)
	Deferred tax liability		(9,186	)
	Total liabilities assumed		(9,220	)
	Net identifiable assets acquired		13,987
	Goodwill		11,613
	Net assets acquired	$	25,600
Schedule of unaudited consolidated pro forma financial information
		Years Ended
		December 31,
	Unaudited Pro Forma Consolidated Information:	2013			2012
	(in thousands)
	Revenue	$	363		$	18,411
	Net income (loss)	$	(61,804	)	$	(49,807	)

Cash_Money_Market_Funds_and_Ma1

Cash, Money Market Funds and Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2014
Cash, Money Market Funds and Marketable Securities
Schedule of cash and available-for-sale securities
	Cash and available for sale securities consisted of the following as of December 31, 2014 and December 31, 2013 (in thousands):
		As of December 31, 2014
		Cost			Unrealized			Unrealized			Fair
					Gain			Loss			Value
	Cash balances	$	24,074		$	—		$	—		$	24,074
	Corporate debt securities, current portion		115,862			—			(110	)		115,752
	Corporate debt securities, non-current portion		17,508			—			(44	)		17,464
	Commercial paper		11,477			22			—			11,499
	Certificate of deposit		350			—			—			350
		$	169,271		$	22		$	(154	)	$	169,139
	Included in cash and cash equivalents	$	24,074		$	—		$	—		$	24,074
	Included in marketable securities		145,197			22			(154	)		145,065
	Total cash and marketable securities	$	169,271		$	22		$	(154	)	$	169,139
		As of December 31, 2013
		Cost			Unrealized			Unrealized			Fair
					Gain			Loss			Value
	Cash balances	$	43,640		$	—		$	—		$	43,640
	Corporate debt securities		30,817			1			(6	)		30,812
	Commercial paper		7,192			6			—			7,198
	Certificate of deposit		350			—			—			350
		$	81,999		$	7		$	(6	)	$	82,000
	Included in cash and cash equivalents	$	43,640		$	—		$	—		$	43,640
	Included in marketable securities		38,359			7			(6	)		38,360
	Total cash and marketable securities	$	81,999		$	7		$	(6	)	$	82,000
Schedule of changes in AOCI associated with the unrealized holding gain on available-for-sale investments	The changes in AOCI associated with the unrealized holding gain on available-for-sale investments during the years ended December 31, 2014 and 2013, were as follows (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Balance, beginning	$	1		$	14		$	4
	Current period changes in fair value,		(133	)		(13	)		10
	Reclassification of earnings,		—			—			—
	Balance, ending	$	(132	)	$	1		$	14

Property_and_Equipment_Tables

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property and Equipment
Schedule of property and equipment
	Property and equipment consist of the following (in thousands):
		December 31,
		2014			2013
	Property and equipment consist of the following:
	Computer equipment	$	3,555		$	3,537
	Computer software		1,102			1,064
	Research equipment		5,986			5,918
	Furniture and fixtures		1,547			1,527
	Leasehold improvements		2,141			2,047
			14,331			14,093
	Less accumulated depreciation and amortization		(11,520	)		(9,973	)
		$	2,811		$	4,120

Accounts_Payable_and_Accrued_E1

Accounts Payable and Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2014
Accounts Payable and Accrued Expenses
Schedule of accounts payable and accrued expenses
	Accounts payable and accrued expenses consist of the following (in thousands):
		December 31,
		2014		2013
	Accounts payable	$	5,874	$	2,146
	Accrued professional fees		473		498
	Accrued contract manufacturing & contract research costs		3,321		1,499
	Accrued compensation and benefits		5,051		4,781
	Accrued facility costs		557		963
	Contingent success fee payable		341		—
	Accrued other		728		275
		$	16,345	$	10,162
Other long-term liabilities
	Other long-term liabilities consist of the following (in thousands):
		December 31,
		2014		2013
	Exit fees	$	450	$	450
	Success fees		—		264
	Employee compensation and benefits		124		—
	Security deposits		14		—
		$	588	$	714

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity
Schedule of fair value weighted-average assumptions
		Years Ended December 31,
		2014			2013			2012
	Expected stock price volatility		81.3	%		82.0	%		77.2	%
	Risk free interest rate		1.9	%		1.3	%		0.8	%
	Expected life of options (years)		6.25			6.25			6.25
	Expected annual dividend per share	$	0.00		$	0.00		$	0.00
Summary of stock options
		Number of			Weighted			Weighted		Aggregate
		Shares			Average			Average		Intrinsic
					Exercise			Remaining		Value
					Price			Contractual Life
		(in thousands)								(in millions)
	Options outstanding, December 31, 2011		6,653.50		$	6.87
	Granted		2,846.60		$	5.34
	Exercised		(437.0	)	$	3.73
	Forfeited		(1,088.9	)	$	7.95
	Options outstanding, December 31, 2012		7,974.20		$	6.35
	Granted		2,481.80		$	3.04
	Exercised		—			—
	Forfeited		(1,414.9	)	$	5.01
	Options outstanding, December 31, 2013		9,041.10		$	5.65
	Granted		2,993.10		$	2.99
	Exercised		(965.6	)	$	3.8
	Forfeited		(1,047.9	)	$	5.76
	Options outstanding, December 31, 2014		10,020.70		$	5.02		6.8 years		$	36.9
	Vested and unvested expected to vest, December 31, 2014		9,441.00		$	5.13		6.7 years		$	34
	Exercisable at December 31, 2014		5,447.90		$	6.45		5.2 years		$	14
Summary of information on the Company's restricted stock
		Number of			Weighted			Weighted			Aggregate
		Shares			Average Grant			Average			Intrinsic
					Date Fair			Remaining			Value
					Value			Years
		(in thousands)									(in millions)
	Non-vested units as of December 31, 2013		—		$	—
	Granted		975		$	2.28
	Vested		—		$	—
	Forfeited		(20	)	$	2.15
	Non-vested units as of December 31,2014		955		$	2.28			0.74		$	5.8
Summary of the stock-based compensation expense recognized in the statements of operations
	The following table summarizes the stock-based compensation expense recognized in the statements of operations (in thousands):
		Years Ended December 31,
		2014			2013			2012
	Stock compensation expense recognized in:
	Research and development expense	$	2,703		$	3,583		$	3,603
	General and administrative expense		3,305			2,594			2,588
	Total stock compensation expense	$	6,008		$	6,177		$	6,191

Assets_and_Liabilities_Measure1

Assets and Liabilities Measured at Fair Value (Tables)	12 Months Ended
	Dec. 31, 2014
Assets and Liabilities Measured at Fair Value
Summary of assets and liabilities subject to fair value measurements	A summary of the fair value of the Company's assets and liabilities aggregated by the level in the fair value hierarchy within which those measurements fall as of December 31, 2014 are identified in the following table (in thousands):
		Level 1		Level 2		Total
	Assets:
	Cash/money market funds	$	24,074	$	—	$	24,074
	Commercial paper		—		11,499		11,499
	Corporate debt securities		—		133,216		133,216
	Certificate of deposit		—		350		350
		$	24,074	$	145,065	$	169,139
		Level 1		Level 2		Level 3		Total
	Liabilities:
	Secured debt	$	—	$	14,350	$	—	$	14,350
	Contingent success fee payable		—		—		341		341
	Contingent consideration payable		—		—		10,700		10,700
		$	—	$	14,350	$	11,041	$	25,391
	A summary of the fair value of the Company's assets and liabilities aggregated by the level in the fair value hierarchy within which those measurements fall as of December 31, 2013 are identified in the following table (in thousands):
		Level 1		Level 2		Total
	Assets:
	Cash/money market funds	$	43,640	$	—	$	43,640
	Commercial paper		—		7,198		7,198
	Corporate debt securities		—		30,812		30,812
	Certificate of deposit		—		350		350
		$	43,640	$	38,360	$	82,000
		Level 1		Level 2		Level 3		Total
	Liabilities:
	Secured debt	$	—	$	14,473	$	—	$	14,473
	Contingent success fee payable		—		—		264		264
	Contingent consideration payable		—		—		10,600		10,600
		$	—	$	14,473		10,864		25,337

Leases_Tables

Leases (Tables)	12 Months Ended
	Dec. 31, 2014
Leases
Schedule of aggregate annual future minimum lease payments under the leases
	(in thousands)	2015			2016			2017		2018		2019 and beyond		Total
	Minimum lease payments	$	2,033		$	2,039		$	1,769	$	1,778	$	297	$	7,916
	Less: income from sublease		(210	)		(180	)		—		—		—		(390	)
	Net minimum lease payments	$	1,823		$	1,859		$	1,769	$	1,778	$	297	$	7,526

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Taxes
Schedule of significant components of the deferred tax assets and liabilities	The significant components of the deferred tax assets and liabilities are as follows (in thousands):
		For Years Ended
		December 31,
		2014			2013
	Current deferred tax asset
	Non-cash stock issue	$	8,990		$	8,172
	Others		2,023			1,343
		$	11,013			9,515
	Non-current deferred tax assets
	Amortization/depreciation		2,910			3,068
	Research tax credit		14,288			13,680
	Net operating loss carry forwards		105,274			79,984
	Deferred revenue		14,626			14,649
	Others		324			682
	Gross deferred tax assets		148,435			121,578
	Deferred tax liability related to business acquisition		(9,186	)		(9,186	)
	Total net deferred tax asset		139,249			112,392
	Less valuation allowance		(148,435	)		(121,578	)
	Net deferred tax assets (liability)	$	(9,186	)	$	(9,186	)
Schedule of reconciliation of the statutory tax rates and the effective tax rates
		Years Ended
		December 31,
		2014			2013			2012
	Statutory rate		(34	)%		(34	)%		(34	)%
	State taxes, net of federal benefit		(4	)		(5	)		(3	)
	Permanent adjustments		1			(1	)		(1	)
	R&D credit		(4	)		(3	)		(8	)
	Other		1			—			1
	Valuation allowance		38			37			38
	Net		(2	)%		(6	)%		(6	)%

ShortTerm_Borrowings_and_LongT1

Short-Term Borrowings and Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2014
Short-Term Borrowings and Long-Term Debt
Schedule of remaining future minimum payments of principal due	The remaining future minimum payments of principal due as of December 31, 2014 are as follows (in thousands):
	Years ending December 31:
	2015	$	4,035
	2016		5,444
	2017		5,521
	2018		—
	2019 and beyond		—
	Total principal obligation		15,000
	Less short-term portion, net of short term debt discount of $195		(3,840	)
	Long-term portion		11,160
	Less debt discount		(650	)
	Long term portion, net of debt discount	$	10,510

Restructuring_Charges_Tables

Restructuring Charges (Tables)	12 Months Ended
	Dec. 31, 2014
Restructuring Charges
Summary of restructuring charges and utilization	The following table summarizes the restructuring charges and utilization for the year ended December 31, 2014 (in thousands):
		Balance as of		Charges		Cash Payments			Adjustments			Balance as of
		December 31,										December 31,
		2013										2014
	Employment termination costs	$	1,139	$	—	$	(1,139	)	$	—		$	—
	Facilities consolidation		703		—		(357	)		(63	)		283
	Total	$	1,842	$	—	$	(1,496	)	$	(63	)	$	283

Earnings_per_Share_Tables

Earnings per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings per Share
Schedule of reconciliation of the numerator and denominator used in computing basic and diluted net loss attributable to common stockholders per common share	The following table provides a reconciliation of the numerator and denominator used in computing basic and diluted net loss attributable to common stockholders per common share (in thousands except share amounts):
		Years Ended December 31,
		2014			2013			2012
	Historical
	Numerator:
	Net loss attributable to common stockholders	$	(68,926	)	$	(59,633	)	$	(48,785	)
	Denominator:
	Weighted average common shares outstanding — basic and diluted		74,444,157			51,286,059			45,565,217
Schedule of potential shares of common stock that were excluded from the computation as they were anti-dilutive using the treasury stock method	The table below presents potential shares of common stock that were excluded from the computation as they were anti-dilutive using the treasury stock method (in thousands):
		Year ended December 31,
		2014			2013			2012
	Options to purchase common stock		10,021			9,041			7,974
	Outstanding warrants, convertible to common stock		1,600			3,004			1,405
	Unvested restricted stock units		955			—			—
	Total number of potentially issuable shares		12,576			12,045			9,379

Selected_Quarterly_Financial_D1

Selected Quarterly Financial Data (Unaudited - in thousands except per share data) (Tables)	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Financial Data (Unaudited - in thousands except per share data)
Schedule of selected quarterly financial data
	Selected Quarterly Financial Data (Unaudited — in thousands except per share data)
			Quarters Ended
			March 31			June 30			September 30			December 31
	2014
	Net loss		$	(15,943	)	$	(14,614	)	$	(17,149	)	$	(21,220	)
	Basic and diluted net loss per common share (1)			(0.25	)		(0.22	)		(0.22	)		(0.24	)
	2013
	Net loss		$	(17,458	)	$	(15,349	)	$	(14,589	)	$	(12,237	)
	Basic and diluted net loss per common share (1)			(0.35	)		(0.31	)		(0.29	)		(0.22	)
	-1	Per common share amounts for the quarters and full years have been calculated separately. Accordingly, quarterly amounts do not add to the annual amounts because of differences on the weighted-average common shares outstanding during each period principally due to the effect of the Company issuing shares of its common stock during the year.

Description_of_Business_Detail

Description of Business (Details) (USD $)	12 Months Ended	1 Months Ended		3 Months Ended
	Dec. 31, 2014	Nov. 30, 2013	Jul. 31, 2014	Jul. 31, 2014	Nov. 30, 2014	Dec. 31, 2013
Corporate Information, Status of Operations and Management Plans
Stock issued from ATM transactions	$38,636,000
Accumulated deficit	447,448,000					378,522,000
Common Stock, Par or Stated Value Per Share	$0.01				$0.01	$0.01
SPA
Corporate Information, Status of Operations and Management Plans
Proceeds received from private placement		15,000,000
GSK | SPA
Corporate Information, Status of Operations and Management Plans
Stock issued from collaboration agreement (in shares)		1,500,000
Warrant term		1 year
Exercise price of warrants (in dollars per share)	2.5	2.5
Aggregate offering proceeds		15,000,000
Equity stake in the Company (as a percent)	0.00%
GSK | Revised Agreement
Corporate Information, Status of Operations and Management Plans
Number of major markets outside the U.S. from whom parties to contractual arrangement is eligible to receive single-digit royalties on net sales		8
Number of major markets outside the U.S. from whom parties to contractual arrangement is eligible to receive post-approval and sales-based milestones		8
Other consideration paid		0
Redmile Group | SPA
Corporate Information, Status of Operations and Management Plans
Stock issued from collaboration agreement (in shares)		6,000,000
Cowen and Company, LLC
Corporate Information, Status of Operations and Management Plans
Stock issued from ATM transactions			38,600,000
Stock issued from ATM transactions (in shares)			14,300,000
Stock issued from collaboration agreement (in shares)				38,600,000
Aggregate offering proceeds			$40,000,000
Common Stock, Par or Stated Value Per Share			$0.01	$0.01

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2014
Minimum
Property and Equipment
Estimated useful lives	3 years
Maximum
Property and Equipment
Estimated useful lives	5 years

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details 2)	1 Months Ended	0 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	31-May-14	Dec. 31, 2014
			item
Stock-Based Compensation
Number of stock-based employee compensation plans			3
2007 Plan and 2007 Director Plan
Equity Incentive Plan
Additional shares available for issuance	6
2007 Plan and 2007 Director Plan | Maximum
Equity Incentive Plan
Maximum number of restricted stock, RSUs, stock grants or similar awards that may be issued	1.5	1.1

Summary_of_Significant_Account4

Summary of Significant Accounting Policies (Details 3)	12 Months Ended
	Dec. 31, 2014
	item
Segment Information
Number of business segments	1

Acquisition_of_Callidus_Biopha2

Acquisition of Callidus Biopharma, Inc. (Details) (USD $)	12 Months Ended			0 Months Ended	1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 30, 2013	Nov. 30, 2013	Nov. 30, 2014
Acquisition of Callidus Biopharma, Inc.
Common stock, par value (in dollars per share)	$0.01	$0.01				$0.01
Contingent consideration payable	$10,700,000	$10,600,000		$10,600,000	$10,600,000
Changes in fair value of contingent consideration payable	100,000
Allocation of the purchase consideration, including the contingent acquisition consideration payable
Contingent acquisition consideration payable	10,700,000	10,600,000		10,600,000	10,600,000
Goodwill	11,613,000	11,613,000
Unaudited Pro Forma Consolidated Information:
Revenue		363,000	18,411,000
Net income (loss)		-61,804,000	-49,807,000
Callidus
Acquisition of Callidus Biopharma, Inc.
Common stock issued on acquisition (in shares)	25,000				7,200,000
Common stock, par value (in dollars per share)				$0.01	$0.01
Shares issued	25,000
Maximum merger consideration to be transferred					130,000,000
Milestone payment that can be settled in equity					40,000,000
Number of trading days immediately preceding the date of payment on basis of which issue price will be determined					10 days
Discount rate (as a percent)					13.00%
Contingent consideration payable	10,700,000			10,600,000	10,600,000
Changes in fair value of contingent consideration payable	100,000
Intangible assets-(IPR&D)				23,000,000	23,000,000
Allocation of the purchase consideration, including the contingent acquisition consideration payable
Upfront equity payments				15,000,000
Contingent acquisition consideration payable	10,700,000			10,600,000	10,600,000
Total consideration				25,600,000
Cash and cash equivalents				34,000	34,000
Property, plant and equipment				173,000	173,000
Intangible assets-(IPR&D)				23,000,000	23,000,000
Total identifiable assets acquired				23,207,000	23,207,000
Accounts payable				-34,000	-34,000
Deferred tax liability				-9,186,000	-9,186,000
Total liabilities assumed				-9,220,000	-9,220,000
Net identifiable assets acquired				13,987,000	13,987,000
Goodwill				11,613,000	11,613,000
Net assets acquired				25,600,000	25,600,000
Deferred tax liabilities relates to the tax impact of future amortization or possible impairments associated with identified intangible assets acquired				9,200,000	9,200,000
Acquisition-related transaction costs		500,000
Callidus | Maximum
Acquisition of Callidus Biopharma, Inc.
Additional payment to be made upon achievement of clinical milestone					35,000,000
Additional payment to be made upon achievement of regulatory approval					$105,000,000

Goodwill_Details

Goodwill (Details) (USD $)	12 Months Ended	1 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Nov. 30, 2013
Impairment of goodwill	$0
Changes in goodwill
Change in goodwill	0
Callidus
Changes in goodwill
Change in goodwill		$11,600

Intangible_Assets_Details

Intangible Assets (Details) (USD $)	12 Months Ended	1 Months Ended
	Dec. 31, 2014	Nov. 30, 2013
Impairment of IPR&D	$0
Callidus
Changes in IPR&D
Change in IPR&D		$23,000,000

Cash_Money_Market_Funds_and_Ma2

Cash, Money Market Funds and Marketable Securities (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash, Money Market Funds, and Marketable Securities
Cash and cash equivalents, Amortized Cost	$24,074,000	$43,640,000	$33,971,000	$25,668,000
Marketable securities, Amortized Cost	145,197,000	38,359,000
Unrealized Gain	-22,000	-7,000
Unrealized Loss	-154,000	-6,000
Cash and cash equivalents, Fair Value	24,074,000	43,640,000
Marketable securities, Fair Value	145,065,000	38,360,000
Marketable securities, Fair Value current portion	127,601,000	38,360,000
Marketable securities, Fair Value non-current portion	17,464,000
Cash, Cash Equivalents, and Short-term Investments, Total	169,271,000	81,999,000
Cash and marketable securities, Fair Value	169,139,000	82,000,000
Available-for-sale investments
Realized gain (loss) on securities available-for-sale	0	0
Fair value of available for sale securities in unrealized loss positions	129,200,000	23,600,000
Changes in AOCI associated with the unrealized holding gain on available-for-sale investments
Balance, beginning	1,000	14,000	4,000
Current period changes in fair value	-133,000	-13,000	10,000
Balance, ending	-132,000	1,000	14,000
Corporate debt securities
Cash, Money Market Funds, and Marketable Securities
Marketable securities, Amortized Cost		30,817,000
Marketable securities, Amortized cost current portion	115,862,000
Marketable securities, Amortized cost non-current portion	17,508,000
Unrealized Gain		-1,000
Unrealized Loss		-6,000
Unrealized Loss current portion	-110,000
Unrealized Loss Non-current portion	-44,000
Marketable securities, Fair Value		30,812,000
Marketable securities, Fair Value current portion	115,752,000
Marketable securities, Fair Value non-current portion	17,464,000
Commercial paper
Cash, Money Market Funds, and Marketable Securities
Marketable securities, Amortized Cost	11,477,000	7,192,000
Unrealized Gain	-22,000	-6,000
Marketable securities, Fair Value	11,499,000	7,198,000
Certificate of deposit
Cash, Money Market Funds, and Marketable Securities
Marketable securities, Amortized Cost	350,000	350,000
Marketable securities, Fair Value	$350,000	$350,000

Property_and_Equipment_Details

Property and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property and Equipment
Property and equipment, gross	$14,331,000	$14,093,000
Less accumulated depreciation and amortization	-11,520,000	-9,973,000
Property and equipment, net	2,811,000	4,120,000
Depreciation and amortization expense	1,547,000	1,719,000	1,705,000
Capital lease obligations outstanding	0
Computer equipment
Property and Equipment
Property and equipment, gross	3,555,000	3,537,000
Computer software
Property and Equipment
Property and equipment, gross	1,102,000	1,064,000
Research equipment
Property and Equipment
Property and equipment, gross	5,986,000	5,918,000
Furniture and fixtures
Property and Equipment
Property and equipment, gross	1,547,000	1,527,000
Leasehold improvements
Property and Equipment
Property and equipment, gross	$2,141,000	$2,047,000

Accounts_Payable_and_Accrued_E2

Accounts Payable and Accrued Expenses (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accrued expenses
Accounts payable	$5,874	$2,146
Accrued professional fees	473	498
Accrued contract manufacturing & contract research costs	3,321	1,499
Accrued compensation and benefits	5,051	4,781
Accrued facility costs	557	963
Contingent success fee payable	341
Accrued other	728	275
Accounts payable and accrued expenses	16,345	10,162
Other long-term liabilities
Exit fees	450	450
Success fees		264
Employee compensation and benefits	124
Security deposits	14
Total Other long-term liabilities	$588	$714

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)	1 Months Ended	12 Months Ended			1 Months Ended	3 Months Ended
	Nov. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 30, 2013	Jul. 31, 2014
		item
Collaborative Agreements
Authorized number of shares of common stock		125,000,000	125,000,000
Voting right for each share held, number		1
Common stock issued (in shares)	15,900,000
Common stock, par value (in dollars per share)	$0.01	$0.01	$0.01
Price per unit (in dollars per share)	$6.50
Aggregate offering proceeds from issuance of common stock (in dollars)	$103,500,000
Underwriting fees incurred on issue of common stock	6,200,000
Legal fees incurred on issue of common stock	100,000
Net proceeds from the issuance of common stock	97,200,000	135,805,000	15,000,000	80,195,000
Offering price (in dollars per share)		$2.12
Total purchase price (in dollars)				18,140,000
Number of inputs used to determine the value of the warrants		6
Warrants
Collaborative Agreements
Exercise price of warrants (in dollars per share)		$2.50
Remaining term of the warrants		1 year
Volatility (as a percent)		93.50%
Annual rate of dividends (as a percent)		0.00%
Riskless rate of return (as a percent)		0.12%
Value of the warrants		1,000,000
Callidus
Collaborative Agreements
Common stock, par value (in dollars per share)					$0.01
Common stock issued on acquisition (in shares)		25,000			7,200,000
Shares issued		25,000
SPA
Collaborative Agreements
Proceeds received from private placement					15,000,000
GSK | SPA
Collaborative Agreements
Stock issued from collaboration agreement (in shares)					1,500,000
Offering price (in dollars per share)					$2
Warrants issued (in shares)					1,600,000
Exercise price of warrants (in dollars per share)		2.5			2.5
Equity stake in the Company (as a percent)		0.00%
Warrant term					1 year
Redmile Group | SPA
Collaborative Agreements
Price per unit (in dollars per share)					$2
Stock issued from collaboration agreement (in shares)					6,000,000
Number of shares represented by units issued					6,000,000
Number of shares of common stock sold in a unit					1
Number of warrants sold in a unit (in shares)					0.267
Cowen and Company, LLC
Collaborative Agreements
Common stock issued (in shares)						14,300,000
Common stock, par value (in dollars per share)						$0.01
Aggregate offering proceeds from issuance of common stock (in dollars)						40,000,000
Legal fees incurred on issue of common stock						300,000
Fixed Commission Rate as Percentage of Gross Proceeds Per Share Sold						3.00%
Commission expenses incurred on issue of common stock						$1,100,000
Stock issued from collaboration agreement (in shares)						38,600,000

Stockholders_Equity_Details_2

Stockholders' Equity (Details 2) (USD $)	12 Months Ended	1 Months Ended		0 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Apr. 30, 2014	Jun. 30, 2014	31-May-14
Stockholders' Equity
Deferred compensation	0.1
Common stock options
Stockholders' Equity
Maximum term of option	10 years
Restricted Stock Units (RSUs) [Member] | Awards vesting on first anniversary
Stockholders' Equity
Vesting rights percentage on the 13th month anniversary		50.00%
Restricted Stock Units (RSUs) [Member] | Awards vesting after first anniversary
Stockholders' Equity
Vesting rights percentage on the 20th month anniversary		50.00%
2002 Plan and 2007 Plan | Common stock options
Stockholders' Equity
Vesting rights percentage on the 13th month anniversary	25.00%
Additional percentage of options that will vest each month after first anniversary	2.08%
Percentage of shares vested that may be exercised in whole or part	100.00%
2007 Plan and 2007 Director Plan
Stockholders' Equity
Additional shares available for issuance			6,000,000
2007 Plan and 2007 Director Plan | Maximum
Stockholders' Equity
Maximum number of restricted stock, RSUs, stock grants or similar awards that may be issued			1,500,000	1,100,000
2007 Plan and 2007 Director Plan | Maximum | Common stock options
Stockholders' Equity
Number of shares reserved for issuance	6,595,880

Stockholders_Equity_Details_3

Stockholders' Equity (Details 3) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock compensation expense
Total stock compensation expense	$6,008	$6,177	$6,191
Research and development expense
Stock compensation expense
Total stock compensation expense	2,703	3,583	3,603
General and administrative expense
Stock compensation expense
Total stock compensation expense	$3,305	$2,594	$2,588

Stockholders_Equity_Details_4

Stockholders' Equity (Details 4) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair value weighted-average assumptions:
Minimum stock price volatility (as a percent)	75.00%
Common stock options
Fair value weighted-average assumptions:
Expected stock price volatility (as a percent)	81.30%	82.00%	77.20%
Risk free interest rate (as a percent)	1.90%	1.30%	0.80%
Expected life of options	6 years 3 months	6 years 3 months	6 years 3 months
Expected annual dividend per share (in dollars per share)	$0	$0	$0
Weighted-average grant-date fair value per share of options granted (in dollars per share)	$2.12	$2.14	$3.31
Number of Shares
Balance at the beginning of the period (in shares)	9,041,100	7,974,200	6,653,500
Options granted (in shares)	2,993,100	2,481,800	2,846,600
Options exercised (in shares)	-965,600	0	-437,000
Options forfeited (in shares)	-1,047,900	-1,414,900	-1,088,900
Balance at the end of the period (in shares)	10,020,700	9,041,100	7,974,200
Vested and unvested expected to vest at the end of the period (in shares)	9,441,000
Exercisable at the end of the period (in shares)	5,447,900
Weighted Average Exercise Price
Balance at the beginning of the period (in dollars per share)	$5.65	$6.35	$6.87
Options granted (in dollars per share)	$2.99	$3.04	$5.34
Options exercised (in dollars per share)	$3.80		$3.73
Options forfeited (in dollars per share)	$5.76	$5.01	$7.95
Balance at the end of the period (in dollars per share)	$5.02	$5.65	$6.35
Vested and unvested expected to vest at the end of the period (in dollars per share)	$5.13
Exercisable at the end of the period (in dollars per share)	$6.45
Weighted Average Remaining Contractual Life
Balance at the end of the period	6 years 9 months 18 days
Vested and unvested expected to vest at the end of the period	6 years 8 months 12 days
Exercisable at the end of the period	5 years 2 months 12 days
Aggregate Intrinsic Value
Aggregate intrinsic value of options outstanding (in dollars)	$36,900
Aggregate intrinsic value of options vested and unvested expected to vest (in dollars)	34,000
Aggregate intrinsic value of options exercisable (in dollars)	14,000
Aggregate intrinsic value of options exercised (in dollars)	2,800,000		900,000
Options exercised (in shares)	-965,600	0	-437,000
Total unrecognized compensation cost related to non-vested stock options granted (in dollars)	7,700,000
Period of recognition compensation cost	2 years 3 months 18 days
Cash proceeds from stock options exercised (in dollars)	3,700,000		1,600,000
Restricted stock
Aggregate Intrinsic Value
Total unrecognized compensation cost related to non-vested stock options granted (in dollars)	1,100,000
Period of recognition compensation cost	8 months 27 days
Restricted stock awards (in shares)	955,000
Number of Shares
Granted (in shares)	975,000
Vested (in shares)	0
Forfeited (in shares)	-20,000
Non-vested units at the end of the period (in shares)	955,000
Weighted Average Grant Date Fair Value
Granted (in dollars per share)	$2.28
Forfeited (in dollars per share)	$2.15
Non-vested units at the end of the period (in dollars per share)	$2.28
Weighted Average Remaining Years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms	8 months 27 days
Aggregate Intrinsic Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested	$5,800,000

Assets_and_Liabilities_Measure2

Assets and Liabilities Measured at Fair Value (Details) (USD $)	1 Months Ended	12 Months Ended
	Nov. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Assets and Liabilities Measured at Fair Value
Transfer of assets from Level 1 to Level 2		$0
Transfer of assets from Level 2 to Level 1		0
Assets:
Cash/money market funds		24,074,000	43,640,000	33,971,000	25,668,000
Liabilities:
Contingent consideration payable	10,600,000	10,700,000	10,600,000
Callidus
Liabilities:
Contingent consideration payable	10,600,000	10,700,000
Changes in Level 3 liability
Discount rate (as a percent)	13.00%
Level 1
Assets:
Cash/money market funds		24,074,000	43,640,000
Fair value of assets		24,074,000	43,640,000
Level 2
Assets:
Fair value of assets		145,065,000	38,360,000
Liabilities:
Secured debt		14,350,000
Fair value of liabilities		14,350,000
Level 2 | Commercial paper
Assets:
Fair value of assets		11,499,000	7,198,000
Level 2 | Corporate debt securities
Assets:
Fair value of assets		133,216,000	30,812,000
Level 2 | Certificate of deposit
Assets:
Fair value of assets		350,000	350,000
Level 3
Assets and Liabilities Measured at Fair Value
Warrant liability			264,000
Liabilities:
Contingent success fee payable		341,000
Warrant liability			264,000
Contingent consideration payable		10,700,000	10,600,000
Fair value of liabilities		11,041,000	10,864,000
Changes in Level 3 liability
Increase/(Decrease) in fair value		200,000	10,000,000
Addition of contingent consideration payable		100,000	10,600,000
Contingent success fee payable increase		77,000
Decrease in fair value of the warrant liability			900,000
Total
Assets and Liabilities Measured at Fair Value
Warrant liability			264,000
Assets:
Cash/money market funds		24,074,000	43,640,000
Fair value of assets		169,139,000	82,000,000
Liabilities:
Secured debt		14,350,000	14,473,000
Contingent success fee payable		341,000
Warrant liability			264,000
Contingent consideration payable		10,700,000	10,600,000
Fair value of liabilities		25,391,000	25,337,000
Total | Commercial paper
Assets:
Fair value of assets		11,499,000	7,198,000
Total | Corporate debt securities
Assets:
Fair value of assets		133,216,000	30,812,000
Total | Certificate of deposit
Assets:
Fair value of assets		350,000	350,000
2013 Loan Agreement
Financial assets and liabilities subject to fair value measurements
Fair value of contingent payment		300,000
Period of trigger event within which success fee is payable		6 months
Period of effectiveness of trigger event from closing of loan		5 years
2013 Loan Agreement | Level 3
Changes in Level 3 liability
Contingent success fee payable increase			300,000
2013 Loan Agreement | Maximum | Level 3
Liabilities:
Contingent success fee payable		$400,000

401k_Plan_Details

401(k) Plan (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
401 (k) Plan
Maximum contribution by the company as a percentage of employee's salary and bonus paid during the year	5.00%
Total contribution to the plan (in dollars)	$0.60	$0.70	$0.70

Leases_Details

Leases (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	item
	sqft
Operating Leases
Area of laboratory and office space leased (in square feet)	73,646
Number of times lease term may be extended	2
Extended additional term of lease agreement	5 years
Minimum lease payments
2015	$2,033,000
2016	2,039,000
2017	1,769,000
2018	1,778,000
2018 and beyond	297,000
Total	7,916,000
Less: income from sublease
2015	-210,000
2016	-180,000
Total	-390,000
Net minimum lease payments
2015	1,823,000
2016	1,859,000
2017	1,769,000
2018	1,778,000
2019 and beyond	297,000
Total	7,526,000
Operating Leases, Rent Expense, Net	$2,400,000	$2,600,000	$2,600,000

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Income Taxes
Recognized interest and penalties	$0
Accrual for interest and penalties	0
Accrual for uncertain tax positions	0
Current deferred tax asset
Non-cash stock issue	8,990,000	8,172,000
Others	2,023,000	1,343,000
Total current deferred tax asset	11,013,000	9,515,000
Non-current deferred tax assets
Amortization/depreciation	2,910,000	3,068,000
Research tax credit	14,288,000	13,680,000
Net operating loss carry forwards	105,274,000	79,984,000
Deferred revenue	14,626,000	14,649,000
Others	324,000	682,000
Gross deferred tax assets	148,435,000	121,578,000
Deferred tax liability related to business acquisition	-9,186,000	-9,186,000
Total net deferred tax asset	139,249,000	112,392,000
Less valuation allowance	-148,435,000	-121,578,000
Net deferred tax assets (liability)	-9,186,000	-9,186,000
Increase in the valuation allowance	$26,800,000	$26,300,000

Income_Taxes_Details_2

Income Taxes (Details 2) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Net operating loss carry forwards
Maximum change in ownership percentage allowed before statutory limitations imposed on the availability of net operating losses	50.00%
Period for measuring the change in ownership	3 years
U.S. Federal NOL carryforward period	20 years
Tax benefit associated with exercise of stock options to be recorded in additional paid-in capital on recognition of associated NOL	$0.20
Federal
Net operating loss carry forwards
Amount of net operating loss carry forwards	268.5
State
Net operating loss carry forwards
Amount of net operating loss carry forwards	235.5
Forecast
Net operating loss carry forwards
Amount of net operating loss carry forwards	$397

Income_Taxes_Details_3

Income Taxes (Details 3) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of the statutory tax rates and the effective tax rates
Statutory rate (as a percent)	-34.00%	-34.00%	-34.00%
State taxes, net of federal benefit (as a percent)	-4.00%	-5.00%	-3.00%
Permanent adjustments (as a percent)	1.00%	-1.00%
R&D credit (as a percent)	-4.00%	-3.00%	-8.00%
Other (as a percent)	1.00%		1.00%
Valuation allowance (as a percent)	38.00%	37.00%	38.00%
Net (as a percent)	-2.00%	-6.00%	-6.00%
Income tax benefit from the sale of net operating losses and research and development credits	$1.10	$3.50	$3.20

Licenses_Details

Licenses (Details) (MSSM, USD $)	12 Months Ended
	Dec. 31, 2014
MSSM
Licenses
Upfront and annual license fees paid	$0
Potential milestone payments	$0

Collaborative_Agreements_Detai

Collaborative Agreements (Details) (USD $)	1 Months Ended	3 Months Ended	12 Months Ended			1 Months Ended
	Nov. 30, 2014	Sep. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 30, 2013
Collaborative Agreements
Price per share of common stock issued as part of the license and collaboration agreement (in dollars per share)			$2.12
Total value of the equity investment to the company	$97,200,000		$135,805,000	$15,000,000	$80,195,000
Pass-through milestone payment		800,000
Total purchase price (in dollars)					18,140,000
Research revenue for work performed under cost sharing arrangement			1,224,000	363,000	11,591,000
GSK | SPA
Collaborative Agreements
Stock issued from collaboration agreement (in shares)						1,500,000
Price per share of common stock issued as part of the license and collaboration agreement (in dollars per share)						$2
GSK | Revised Agreement
Collaborative Agreements
Upfront payment received						0
Number of major markets outside the U.S. from whom parties to contractual arrangement is eligible to receive post-approval and sales-based milestones						8
GSK | Revised Agreement | Maximum
Collaborative Agreements
Potential milestone payments upon achievement of post-approval and sales-based milestones						40,000,000
Biogen Idec
Collaborative Agreements
Research revenue for work performed under cost sharing arrangement			$1,200,000

ShortTerm_Borrowings_and_LongT2

Short-Term Borrowings and Long-Term Debt (Details) (USD $)	1 Months Ended		12 Months Ended
	Feb. 29, 2012	Dec. 31, 2013	Dec. 31, 2014
			item
Short-Term Borrowings and Long-Term Debt
Long-term portion			$11,160,000
Less debt discount			-650,000
Remaining future minimum payments of principal due
2015			4,035,000
2016			5,444,000
2017			5,521,000
Total principal obligation			15,000,000
Less short-term portion, net of short term debt discount of $195		-299,000	-3,840,000
Long-term portion			11,160,000
Less debt discount			-650,000
Long term portion, net of debt discount		14,174,000	10,510,000
Debt discount short term			195,000
Level 3
Short-Term Borrowings and Long-Term Debt
Contingent success fee payable			341,000
2011 Loan Agreement
Short-Term Borrowings and Long-Term Debt
Long-term portion			0
Amount borrowed	1,000,000
Period for repayment of debt	2 years 6 months
Remaining future minimum payments of principal due
Long-term portion			0
2013 Loan Agreement
Short-Term Borrowings and Long-Term Debt
Maximum amount of loan		25,000,000
Fixed interest rate (as a percent)			8.50%
Long-term portion			15,000,000
Amount borrowed		15,000,000
Less debt discount			-800,000
Number of equal monthly installments for repayment of debt			33
Debt facility fee			100,000
Contingent exit fee payable			400,000
Fair value of contingent payment			300,000
Period of trigger event within which success fee is payable			6 months
Period of effectiveness of trigger event from closing of loan			5 years
Remaining future minimum payments of principal due
Long-term portion			15,000,000
Less debt discount			-800,000
2013 Loan Agreement | Maximum
Short-Term Borrowings and Long-Term Debt
Amount available for borrowing			10,000,000
2013 Loan Agreement | Maximum | Level 3
Short-Term Borrowings and Long-Term Debt
Contingent success fee payable			$400,000

Restructuring_Charges_Details

Restructuring Charges (Details) (USD $)	3 Months Ended	12 Months Ended			1 Months Ended		3 Months Ended
	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 30, 2013	Dec. 31, 2013	Dec. 31, 2014
					item	item
Restructuring charges
Restructuring charges	$2,000,000	($63,000)	$1,988,000
Lease payments		2,400,000	2,600,000	2,600,000
Summary of restructuring charges and utilization
Balance at the beginning of the period		1,842,000
Charges	-2,000,000	63,000	-1,988,000
Cash payments		-1,496,000
Adjustments		-63,000
Balance at the end of the period	1,842,000	283,000	1,842,000			1,842,000	283,000
Employment termination costs
Restructuring charges
Employees eliminated (as a percent)					14.00%
Number of employees eliminated					15
Restructuring charges	1,200,000
Summary of restructuring charges and utilization
Balance at the beginning of the period		1,139,000
Charges	-1,200,000
Cash payments		-1,139,000
Balance at the end of the period	1,139,000		1,139,000			1,139,000
Facilities consolidation
Restructuring charges
Number of subleased locations that were closed in consolidation						1
Restructuring charges	800,000
Lease payments							700,000
Write-down of the net book value of fixed assets	100,000
Summary of restructuring charges and utilization
Balance at the beginning of the period		703,000
Charges	-800,000
Cash payments		-357,000
Adjustments		-63,000
Balance at the end of the period	$703,000	$283,000	$703,000			$703,000	$283,000

Earnings_per_Share_Details

Earnings per Share (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Antidilutive securities
Antidilutive securities excluded from computation of diluted earnings per share (in shares)	12,576,000	12,045,000	9,379,000
Numerator:
Net loss attributable to common stockholders	($68,926)	($59,633)	($48,785)
Denominator
Weighted average common shares outstanding - basic and diluted	74,444,157	51,286,059	45,565,217
Common stock options
Antidilutive securities
Antidilutive securities excluded from computation of diluted earnings per share (in shares)	10,021,000	9,041,000	7,974,000
Warrants
Antidilutive securities
Antidilutive securities excluded from computation of diluted earnings per share (in shares)	1,600,000	3,004,000	1,405,000
Restricted Stock Units (RSUs) [Member]
Antidilutive securities
Antidilutive securities excluded from computation of diluted earnings per share (in shares)	955,000

Selected_Quarterly_Financial_D2

Selected Quarterly Financial Data (Unaudited - in thousands except per share data) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Selected Quarterly Financial Data
Net loss	($21,220)	($17,149)	($14,614)	($15,943)	($12,237)	($14,589)	($15,349)	($17,458)	($68,926)	($59,633)	($48,785)
Basic and diluted net loss per common share (in dollars per share)	($0.24)	($0.22)	($0.22)	($0.25)	($0.22)	($0.29)	($0.31)	($0.35)	($0.93)	($1.16)	($1.07)